src/HOL/Nat.thy
author haftmann
Thu, 14 May 2009 15:09:47 +0200
changeset 31155 92d8ff6af82c
parent 31100 6a2e67fe4488
child 31714 347e9d18f372
permissions -rw-r--r--
monomorphic code generation for power operations
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
923
ff1574a81019 new version of HOL with curried function application
clasohm
parents:
diff changeset
     1
(*  Title:      HOL/Nat.thy
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
     2
    Author:     Tobias Nipkow and Lawrence C Paulson and Markus Wenzel
923
ff1574a81019 new version of HOL with curried function application
clasohm
parents:
diff changeset
     3
9436
62bb04ab4b01 rearranged setup of arithmetic procedures, avoiding global reference values;
wenzelm
parents: 7702
diff changeset
     4
Type "nat" is a linear order, and a datatype; arithmetic operators + -
30496
7cdcc9dd95cb vague cleanup in arith proof tools setup: deleted dead code, more proper structures, clearer arrangement
haftmann
parents: 30242
diff changeset
     5
and * (for div and mod, see theory Divides).
923
ff1574a81019 new version of HOL with curried function application
clasohm
parents:
diff changeset
     6
*)
ff1574a81019 new version of HOL with curried function application
clasohm
parents:
diff changeset
     7
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
     8
header {* Natural numbers *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
     9
15131
c69542757a4d New theory header syntax.
nipkow
parents: 14740
diff changeset
    10
theory Nat
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
    11
imports Inductive Ring_and_Field
23263
0c227412b285 tuned boostrap
haftmann
parents: 23001
diff changeset
    12
uses
0c227412b285 tuned boostrap
haftmann
parents: 23001
diff changeset
    13
  "~~/src/Tools/rat.ML"
0c227412b285 tuned boostrap
haftmann
parents: 23001
diff changeset
    14
  "~~/src/Provers/Arith/cancel_sums.ML"
30496
7cdcc9dd95cb vague cleanup in arith proof tools setup: deleted dead code, more proper structures, clearer arrangement
haftmann
parents: 30242
diff changeset
    15
  "Tools/arith_data.ML"
7cdcc9dd95cb vague cleanup in arith proof tools setup: deleted dead code, more proper structures, clearer arrangement
haftmann
parents: 30242
diff changeset
    16
  ("Tools/nat_arith.ML")
24091
109f19a13872 added Tools/lin_arith.ML;
wenzelm
parents: 24075
diff changeset
    17
  "~~/src/Provers/Arith/fast_lin_arith.ML"
109f19a13872 added Tools/lin_arith.ML;
wenzelm
parents: 24075
diff changeset
    18
  ("Tools/lin_arith.ML")
15131
c69542757a4d New theory header syntax.
nipkow
parents: 14740
diff changeset
    19
begin
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    20
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    21
subsection {* Type @{text ind} *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    22
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    23
typedecl ind
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    24
19573
340c466c9605 axiomatization;
wenzelm
parents: 18702
diff changeset
    25
axiomatization
340c466c9605 axiomatization;
wenzelm
parents: 18702
diff changeset
    26
  Zero_Rep :: ind and
340c466c9605 axiomatization;
wenzelm
parents: 18702
diff changeset
    27
  Suc_Rep :: "ind => ind"
340c466c9605 axiomatization;
wenzelm
parents: 18702
diff changeset
    28
where
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    29
  -- {* the axiom of infinity in 2 parts *}
19573
340c466c9605 axiomatization;
wenzelm
parents: 18702
diff changeset
    30
  inj_Suc_Rep:          "inj Suc_Rep" and
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
    31
  Suc_Rep_not_Zero_Rep: "Suc_Rep x \<noteq> Zero_Rep"
19573
340c466c9605 axiomatization;
wenzelm
parents: 18702
diff changeset
    32
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    33
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    34
subsection {* Type nat *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    35
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    36
text {* Type definition *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    37
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
    38
inductive Nat :: "ind \<Rightarrow> bool"
22262
96ba62dff413 Adapted to new inductive definition package.
berghofe
parents: 22191
diff changeset
    39
where
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
    40
    Zero_RepI: "Nat Zero_Rep"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
    41
  | Suc_RepI: "Nat i \<Longrightarrow> Nat (Suc_Rep i)"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    42
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    43
global
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    44
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    45
typedef (open Nat)
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    46
  nat = Nat
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    47
  by (rule exI, unfold mem_def, rule Nat.Zero_RepI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    48
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
    49
constdefs
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    50
  Suc ::   "nat => nat"
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    51
  Suc_def: "Suc == (%n. Abs_Nat (Suc_Rep (Rep_Nat n)))"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    52
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    53
local
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    54
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    55
instantiation nat :: zero
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    56
begin
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    57
28562
4e74209f113e `code func` now just `code`
haftmann
parents: 28514
diff changeset
    58
definition Zero_nat_def [code del]:
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    59
  "0 = Abs_Nat Zero_Rep"
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    60
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    61
instance ..
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    62
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
    63
end
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
    64
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    65
lemma Suc_not_Zero: "Suc m \<noteq> 0"
30686
47a32dd1b86e moved generic arith_tac (formerly silent_arith_tac), verbose_arith_tac (formerly arith_tac) to Arith_Data; simple_arith-tac now named linear_arith_tac
haftmann
parents: 30496
diff changeset
    66
  by (simp add: Zero_nat_def Suc_def Abs_Nat_inject [unfolded mem_def]
27129
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    67
    Rep_Nat [unfolded mem_def] Suc_RepI Zero_RepI Suc_Rep_not_Zero_Rep [unfolded mem_def])
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    68
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    69
lemma Zero_not_Suc: "0 \<noteq> Suc m"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    70
  by (rule not_sym, rule Suc_not_Zero not_sym)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    71
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    72
rep_datatype "0 \<Colon> nat" Suc
27129
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    73
  apply (unfold Zero_nat_def Suc_def)
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    74
     apply (rule Rep_Nat_inverse [THEN subst]) -- {* types force good instantiation *}
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    75
     apply (erule Rep_Nat [unfolded mem_def, THEN Nat.induct])
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    76
     apply (iprover elim: Abs_Nat_inverse [unfolded mem_def, THEN subst])
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    77
    apply (simp_all add: Abs_Nat_inject [unfolded mem_def] Rep_Nat [unfolded mem_def]
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    78
      Suc_RepI Zero_RepI Suc_Rep_not_Zero_Rep [unfolded mem_def]
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    79
      Suc_Rep_not_Zero_Rep [unfolded mem_def, symmetric]
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    80
      inj_Suc_Rep [THEN inj_eq] Rep_Nat_inject)
336807f865ce added nat_induct_tac (works without context);
wenzelm
parents: 27104
diff changeset
    81
  done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    82
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    83
lemma nat_induct [case_names 0 Suc, induct type: nat]:
30686
47a32dd1b86e moved generic arith_tac (formerly silent_arith_tac), verbose_arith_tac (formerly arith_tac) to Arith_Data; simple_arith-tac now named linear_arith_tac
haftmann
parents: 30496
diff changeset
    84
  -- {* for backward compatibility -- names of variables differ *}
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    85
  fixes n
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    86
  assumes "P 0"
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    87
    and "\<And>n. P n \<Longrightarrow> P (Suc n)"
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    88
  shows "P n"
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    89
  using assms by (rule nat.induct) 
21411
a9671d4f7c03 power is now a class
haftmann
parents: 21252
diff changeset
    90
a9671d4f7c03 power is now a class
haftmann
parents: 21252
diff changeset
    91
declare nat.exhaust [case_names 0 Suc, cases type: nat]
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
    92
21672
29c346b165d4 added aliases for nat_recs/cases;
wenzelm
parents: 21456
diff changeset
    93
lemmas nat_rec_0 = nat.recs(1)
29c346b165d4 added aliases for nat_recs/cases;
wenzelm
parents: 21456
diff changeset
    94
  and nat_rec_Suc = nat.recs(2)
29c346b165d4 added aliases for nat_recs/cases;
wenzelm
parents: 21456
diff changeset
    95
29c346b165d4 added aliases for nat_recs/cases;
wenzelm
parents: 21456
diff changeset
    96
lemmas nat_case_0 = nat.cases(1)
29c346b165d4 added aliases for nat_recs/cases;
wenzelm
parents: 21456
diff changeset
    97
  and nat_case_Suc = nat.cases(2)
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
    98
   
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
    99
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   100
text {* Injectiveness and distinctness lemmas *}
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   101
27104
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
   102
lemma inj_Suc[simp]: "inj_on Suc N"
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
   103
  by (simp add: inj_on_def)
791607529f6d rep_datatype command now takes list of constructors as input arguments
haftmann
parents: 26748
diff changeset
   104
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   105
lemma Suc_neq_Zero: "Suc m = 0 \<Longrightarrow> R"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   106
by (rule notE, rule Suc_not_Zero)
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   107
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   108
lemma Zero_neq_Suc: "0 = Suc m \<Longrightarrow> R"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   109
by (rule Suc_neq_Zero, erule sym)
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   110
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   111
lemma Suc_inject: "Suc x = Suc y \<Longrightarrow> x = y"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   112
by (rule inj_Suc [THEN injD])
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   113
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   114
lemma n_not_Suc_n: "n \<noteq> Suc n"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   115
by (induct n) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   116
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   117
lemma Suc_n_not_n: "Suc n \<noteq> n"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   118
by (rule not_sym, rule n_not_Suc_n)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   119
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   120
text {* A special form of induction for reasoning
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   121
  about @{term "m < n"} and @{term "m - n"} *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   122
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   123
lemma diff_induct: "(!!x. P x 0) ==> (!!y. P 0 (Suc y)) ==>
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   124
    (!!x y. P x y ==> P (Suc x) (Suc y)) ==> P m n"
14208
144f45277d5a misc tidying
paulson
parents: 14193
diff changeset
   125
  apply (rule_tac x = m in spec)
15251
bb6f072c8d10 converted some induct_tac to induct
paulson
parents: 15140
diff changeset
   126
  apply (induct n)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   127
  prefer 2
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   128
  apply (rule allI)
17589
58eeffd73be1 renamed rules to iprover
nipkow
parents: 16796
diff changeset
   129
  apply (induct_tac x, iprover+)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   130
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   131
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   132
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   133
subsection {* Arithmetic operators *}
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   134
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   135
instantiation nat :: "{minus, comm_monoid_add}"
25571
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   136
begin
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   137
25571
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   138
primrec plus_nat
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   139
where
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   140
  add_0:      "0 + n = (n\<Colon>nat)"
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   141
  | add_Suc:  "Suc m + n = Suc (m + n)"
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   142
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   143
lemma add_0_right [simp]: "m + 0 = (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   144
  by (induct m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   145
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   146
lemma add_Suc_right [simp]: "m + Suc n = Suc (m + n)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   147
  by (induct m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   148
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   149
declare add_0 [code]
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   150
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   151
lemma add_Suc_shift [code]: "Suc m + n = m + Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   152
  by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   153
25571
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   154
primrec minus_nat
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   155
where
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   156
  diff_0:     "m - 0 = (m\<Colon>nat)"
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   157
  | diff_Suc: "m - Suc n = (case m - n of 0 => 0 | Suc k => k)"
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   158
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   159
declare diff_Suc [simp del]
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   160
declare diff_0 [code]
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   161
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   162
lemma diff_0_eq_0 [simp, code]: "0 - n = (0::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   163
  by (induct n) (simp_all add: diff_Suc)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   164
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   165
lemma diff_Suc_Suc [simp, code]: "Suc m - Suc n = m - n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   166
  by (induct n) (simp_all add: diff_Suc)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   167
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   168
instance proof
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   169
  fix n m q :: nat
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   170
  show "(n + m) + q = n + (m + q)" by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   171
  show "n + m = m + n" by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   172
  show "0 + n = n" by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   173
qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   174
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   175
end
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   176
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   177
instantiation nat :: comm_semiring_1_cancel
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   178
begin
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   179
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   180
definition
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   181
  One_nat_def [simp]: "1 = Suc 0"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   182
25571
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   183
primrec times_nat
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   184
where
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   185
  mult_0:     "0 * n = (0\<Colon>nat)"
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   186
  | mult_Suc: "Suc m * n = n + (m * n)"
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   187
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   188
lemma mult_0_right [simp]: "(m::nat) * 0 = 0"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   189
  by (induct m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   190
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   191
lemma mult_Suc_right [simp]: "m * Suc n = m + (m * n)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   192
  by (induct m) (simp_all add: add_left_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   193
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   194
lemma add_mult_distrib: "(m + n) * k = (m * k) + ((n * k)::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   195
  by (induct m) (simp_all add: add_assoc)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   196
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   197
instance proof
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   198
  fix n m q :: nat
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   199
  show "0 \<noteq> (1::nat)" unfolding One_nat_def by simp
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   200
  show "1 * n = n" unfolding One_nat_def by simp
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   201
  show "n * m = m * n" by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   202
  show "(n * m) * q = n * (m * q)" by (induct n) (simp_all add: add_mult_distrib)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   203
  show "(n + m) * q = n * q + m * q" by (rule add_mult_distrib)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   204
  assume "n + m = n + q" thus "m = q" by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   205
qed
25571
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   206
c9e39eafc7a0 instantiation target rather than legacy instance
haftmann
parents: 25563
diff changeset
   207
end
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   208
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   209
subsubsection {* Addition *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   210
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   211
lemma nat_add_assoc: "(m + n) + k = m + ((n + k)::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   212
  by (rule add_assoc)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   213
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   214
lemma nat_add_commute: "m + n = n + (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   215
  by (rule add_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   216
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   217
lemma nat_add_left_commute: "x + (y + z) = y + ((x + z)::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   218
  by (rule add_left_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   219
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   220
lemma nat_add_left_cancel [simp]: "(k + m = k + n) = (m = (n::nat))"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   221
  by (rule add_left_cancel)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   222
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   223
lemma nat_add_right_cancel [simp]: "(m + k = n + k) = (m=(n::nat))"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   224
  by (rule add_right_cancel)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   225
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   226
text {* Reasoning about @{text "m + 0 = 0"}, etc. *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   227
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   228
lemma add_is_0 [iff]:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   229
  fixes m n :: nat
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   230
  shows "(m + n = 0) = (m = 0 & n = 0)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   231
  by (cases m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   232
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   233
lemma add_is_1:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   234
  "(m+n= Suc 0) = (m= Suc 0 & n=0 | m=0 & n= Suc 0)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   235
  by (cases m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   236
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   237
lemma one_is_add:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   238
  "(Suc 0 = m + n) = (m = Suc 0 & n = 0 | m = 0 & n = Suc 0)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   239
  by (rule trans, rule eq_commute, rule add_is_1)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   240
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   241
lemma add_eq_self_zero:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   242
  fixes m n :: nat
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   243
  shows "m + n = m \<Longrightarrow> n = 0"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   244
  by (induct m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   245
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   246
lemma inj_on_add_nat[simp]: "inj_on (%n::nat. n+k) N"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   247
  apply (induct k)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   248
   apply simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   249
  apply(drule comp_inj_on[OF _ inj_Suc])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   250
  apply (simp add:o_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   251
  done
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   252
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   253
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   254
subsubsection {* Difference *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   255
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   256
lemma diff_self_eq_0 [simp]: "(m\<Colon>nat) - m = 0"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   257
  by (induct m) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   258
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   259
lemma diff_diff_left: "(i::nat) - j - k = i - (j + k)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   260
  by (induct i j rule: diff_induct) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   261
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   262
lemma Suc_diff_diff [simp]: "(Suc m - n) - Suc k = m - n - k"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   263
  by (simp add: diff_diff_left)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   264
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   265
lemma diff_commute: "(i::nat) - j - k = i - k - j"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   266
  by (simp add: diff_diff_left add_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   267
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   268
lemma diff_add_inverse: "(n + m) - n = (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   269
  by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   270
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   271
lemma diff_add_inverse2: "(m + n) - n = (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   272
  by (simp add: diff_add_inverse add_commute [of m n])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   273
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   274
lemma diff_cancel: "(k + m) - (k + n) = m - (n::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   275
  by (induct k) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   276
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   277
lemma diff_cancel2: "(m + k) - (n + k) = m - (n::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   278
  by (simp add: diff_cancel add_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   279
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   280
lemma diff_add_0: "n - (n + m) = (0::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   281
  by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   282
30093
ecb557b021b2 add lemma diff_Suc_1
huffman
parents: 30079
diff changeset
   283
lemma diff_Suc_1 [simp]: "Suc n - 1 = n"
ecb557b021b2 add lemma diff_Suc_1
huffman
parents: 30079
diff changeset
   284
  unfolding One_nat_def by simp
ecb557b021b2 add lemma diff_Suc_1
huffman
parents: 30079
diff changeset
   285
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   286
text {* Difference distributes over multiplication *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   287
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   288
lemma diff_mult_distrib: "((m::nat) - n) * k = (m * k) - (n * k)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   289
by (induct m n rule: diff_induct) (simp_all add: diff_cancel)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   290
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   291
lemma diff_mult_distrib2: "k * ((m::nat) - n) = (k * m) - (k * n)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   292
by (simp add: diff_mult_distrib mult_commute [of k])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   293
  -- {* NOT added as rewrites, since sometimes they are used from right-to-left *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   294
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   295
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   296
subsubsection {* Multiplication *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   297
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   298
lemma nat_mult_assoc: "(m * n) * k = m * ((n * k)::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   299
  by (rule mult_assoc)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   300
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   301
lemma nat_mult_commute: "m * n = n * (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   302
  by (rule mult_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   303
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   304
lemma add_mult_distrib2: "k * (m + n) = (k * m) + ((k * n)::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   305
  by (rule right_distrib)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   306
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   307
lemma mult_is_0 [simp]: "((m::nat) * n = 0) = (m=0 | n=0)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   308
  by (induct m) auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   309
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   310
lemmas nat_distrib =
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   311
  add_mult_distrib add_mult_distrib2 diff_mult_distrib diff_mult_distrib2
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   312
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   313
lemma mult_eq_1_iff [simp]: "(m * n = Suc 0) = (m = Suc 0 & n = Suc 0)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   314
  apply (induct m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   315
   apply simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   316
  apply (induct n)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   317
   apply auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   318
  done
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   319
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   320
lemma one_eq_mult_iff [simp,noatp]: "(Suc 0 = m * n) = (m = Suc 0 & n = Suc 0)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   321
  apply (rule trans)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   322
  apply (rule_tac [2] mult_eq_1_iff, fastsimp)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   323
  done
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   324
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   325
lemma nat_mult_eq_1_iff [simp]: "m * n = (1::nat) \<longleftrightarrow> m = 1 \<and> n = 1"
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   326
  unfolding One_nat_def by (rule mult_eq_1_iff)
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   327
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   328
lemma nat_1_eq_mult_iff [simp]: "(1::nat) = m * n \<longleftrightarrow> m = 1 \<and> n = 1"
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   329
  unfolding One_nat_def by (rule one_eq_mult_iff)
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   330
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   331
lemma mult_cancel1 [simp]: "(k * m = k * n) = (m = n | (k = (0::nat)))"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   332
proof -
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   333
  have "k \<noteq> 0 \<Longrightarrow> k * m = k * n \<Longrightarrow> m = n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   334
  proof (induct n arbitrary: m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   335
    case 0 then show "m = 0" by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   336
  next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   337
    case (Suc n) then show "m = Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   338
      by (cases m) (simp_all add: eq_commute [of "0"])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   339
  qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   340
  then show ?thesis by auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   341
qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   342
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   343
lemma mult_cancel2 [simp]: "(m * k = n * k) = (m = n | (k = (0::nat)))"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   344
  by (simp add: mult_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   345
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   346
lemma Suc_mult_cancel1: "(Suc k * m = Suc k * n) = (m = n)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   347
  by (subst mult_cancel1) simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   348
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   349
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   350
subsection {* Orders on @{typ nat} *}
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   351
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   352
subsubsection {* Operation definition *}
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   353
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   354
instantiation nat :: linorder
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   355
begin
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   356
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   357
primrec less_eq_nat where
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   358
  "(0\<Colon>nat) \<le> n \<longleftrightarrow> True"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   359
  | "Suc m \<le> n \<longleftrightarrow> (case n of 0 \<Rightarrow> False | Suc n \<Rightarrow> m \<le> n)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   360
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   361
declare less_eq_nat.simps [simp del]
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   362
lemma [code]: "(0\<Colon>nat) \<le> n \<longleftrightarrow> True" by (simp add: less_eq_nat.simps)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   363
lemma le0 [iff]: "0 \<le> (n\<Colon>nat)" by (simp add: less_eq_nat.simps)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   364
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   365
definition less_nat where
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   366
  less_eq_Suc_le: "n < m \<longleftrightarrow> Suc n \<le> m"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   367
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   368
lemma Suc_le_mono [iff]: "Suc n \<le> Suc m \<longleftrightarrow> n \<le> m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   369
  by (simp add: less_eq_nat.simps(2))
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   370
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   371
lemma Suc_le_eq [code]: "Suc m \<le> n \<longleftrightarrow> m < n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   372
  unfolding less_eq_Suc_le ..
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   373
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   374
lemma le_0_eq [iff]: "(n\<Colon>nat) \<le> 0 \<longleftrightarrow> n = 0"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   375
  by (induct n) (simp_all add: less_eq_nat.simps(2))
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   376
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   377
lemma not_less0 [iff]: "\<not> n < (0\<Colon>nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   378
  by (simp add: less_eq_Suc_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   379
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   380
lemma less_nat_zero_code [code]: "n < (0\<Colon>nat) \<longleftrightarrow> False"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   381
  by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   382
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   383
lemma Suc_less_eq [iff]: "Suc m < Suc n \<longleftrightarrow> m < n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   384
  by (simp add: less_eq_Suc_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   385
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   386
lemma less_Suc_eq_le [code]: "m < Suc n \<longleftrightarrow> m \<le> n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   387
  by (simp add: less_eq_Suc_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   388
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   389
lemma le_SucI: "m \<le> n \<Longrightarrow> m \<le> Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   390
  by (induct m arbitrary: n)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   391
    (simp_all add: less_eq_nat.simps(2) split: nat.splits)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   392
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   393
lemma Suc_leD: "Suc m \<le> n \<Longrightarrow> m \<le> n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   394
  by (cases n) (auto intro: le_SucI)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   395
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   396
lemma less_SucI: "m < n \<Longrightarrow> m < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   397
  by (simp add: less_eq_Suc_le) (erule Suc_leD)
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   398
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   399
lemma Suc_lessD: "Suc m < n \<Longrightarrow> m < n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   400
  by (simp add: less_eq_Suc_le) (erule Suc_leD)
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   401
26315
cb3badaa192e removed redundant less_trans, less_linear, le_imp_less_or_eq, le_less_trans, less_le_trans (cf. Orderings.thy);
wenzelm
parents: 26300
diff changeset
   402
instance
cb3badaa192e removed redundant less_trans, less_linear, le_imp_less_or_eq, le_less_trans, less_le_trans (cf. Orderings.thy);
wenzelm
parents: 26300
diff changeset
   403
proof
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   404
  fix n m :: nat
27679
haftmann
parents: 27627
diff changeset
   405
  show "n < m \<longleftrightarrow> n \<le> m \<and> \<not> m \<le> n" 
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   406
  proof (induct n arbitrary: m)
27679
haftmann
parents: 27627
diff changeset
   407
    case 0 then show ?case by (cases m) (simp_all add: less_eq_Suc_le)
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   408
  next
27679
haftmann
parents: 27627
diff changeset
   409
    case (Suc n) then show ?case by (cases m) (simp_all add: less_eq_Suc_le)
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   410
  qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   411
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   412
  fix n :: nat show "n \<le> n" by (induct n) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   413
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   414
  fix n m :: nat assume "n \<le> m" and "m \<le> n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   415
  then show "n = m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   416
    by (induct n arbitrary: m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   417
      (simp_all add: less_eq_nat.simps(2) split: nat.splits)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   418
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   419
  fix n m q :: nat assume "n \<le> m" and "m \<le> q"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   420
  then show "n \<le> q"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   421
  proof (induct n arbitrary: m q)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   422
    case 0 show ?case by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   423
  next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   424
    case (Suc n) then show ?case
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   425
      by (simp_all (no_asm_use) add: less_eq_nat.simps(2) split: nat.splits, clarify,
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   426
        simp_all (no_asm_use) add: less_eq_nat.simps(2) split: nat.splits, clarify,
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   427
        simp_all (no_asm_use) add: less_eq_nat.simps(2) split: nat.splits)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   428
  qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   429
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   430
  fix n m :: nat show "n \<le> m \<or> m \<le> n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   431
    by (induct n arbitrary: m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   432
      (simp_all add: less_eq_nat.simps(2) split: nat.splits)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   433
qed
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   434
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   435
end
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   436
29652
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   437
instantiation nat :: bot
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   438
begin
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   439
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   440
definition bot_nat :: nat where
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   441
  "bot_nat = 0"
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   442
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   443
instance proof
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   444
qed (simp add: bot_nat_def)
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   445
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   446
end
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   447
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   448
subsubsection {* Introduction properties *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   449
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   450
lemma lessI [iff]: "n < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   451
  by (simp add: less_Suc_eq_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   452
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   453
lemma zero_less_Suc [iff]: "0 < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   454
  by (simp add: less_Suc_eq_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   455
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   456
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   457
subsubsection {* Elimination properties *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   458
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   459
lemma less_not_refl: "~ n < (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   460
  by (rule order_less_irrefl)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   461
26335
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   462
lemma less_not_refl2: "n < m ==> m \<noteq> (n::nat)"
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   463
  by (rule not_sym) (rule less_imp_neq) 
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   464
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   465
lemma less_not_refl3: "(s::nat) < t ==> s \<noteq> t"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   466
  by (rule less_imp_neq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   467
26335
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   468
lemma less_irrefl_nat: "(n::nat) < n ==> R"
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   469
  by (rule notE, rule less_not_refl)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   470
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   471
lemma less_zeroE: "(n::nat) < 0 ==> R"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   472
  by (rule notE) (rule not_less0)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   473
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   474
lemma less_Suc_eq: "(m < Suc n) = (m < n | m = n)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   475
  unfolding less_Suc_eq_le le_less ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   476
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   477
lemma less_Suc0 [iff]: "(n < Suc 0) = (n = 0)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   478
  by (simp add: less_Suc_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   479
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   480
lemma less_one [iff, noatp]: "(n < (1::nat)) = (n = 0)"
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   481
  unfolding One_nat_def by (rule less_Suc0)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   482
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   483
lemma Suc_mono: "m < n ==> Suc m < Suc n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   484
  by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   485
14302
6c24235e8d5d *** empty log message ***
nipkow
parents: 14267
diff changeset
   486
text {* "Less than" is antisymmetric, sort of *}
6c24235e8d5d *** empty log message ***
nipkow
parents: 14267
diff changeset
   487
lemma less_antisym: "\<lbrakk> \<not> n < m; n < Suc m \<rbrakk> \<Longrightarrow> m = n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   488
  unfolding not_less less_Suc_eq_le by (rule antisym)
14302
6c24235e8d5d *** empty log message ***
nipkow
parents: 14267
diff changeset
   489
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   490
lemma nat_neq_iff: "((m::nat) \<noteq> n) = (m < n | n < m)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   491
  by (rule linorder_neq_iff)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   492
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   493
lemma nat_less_cases: assumes major: "(m::nat) < n ==> P n m"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   494
  and eqCase: "m = n ==> P n m" and lessCase: "n<m ==> P n m"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   495
  shows "P n m"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   496
  apply (rule less_linear [THEN disjE])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   497
  apply (erule_tac [2] disjE)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   498
  apply (erule lessCase)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   499
  apply (erule sym [THEN eqCase])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   500
  apply (erule major)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   501
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   502
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   503
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   504
subsubsection {* Inductive (?) properties *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   505
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   506
lemma Suc_lessI: "m < n ==> Suc m \<noteq> n ==> Suc m < n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   507
  unfolding less_eq_Suc_le [of m] le_less by simp 
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   508
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   509
lemma lessE:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   510
  assumes major: "i < k"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   511
  and p1: "k = Suc i ==> P" and p2: "!!j. i < j ==> k = Suc j ==> P"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   512
  shows P
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   513
proof -
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   514
  from major have "\<exists>j. i \<le> j \<and> k = Suc j"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   515
    unfolding less_eq_Suc_le by (induct k) simp_all
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   516
  then have "(\<exists>j. i < j \<and> k = Suc j) \<or> k = Suc i"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   517
    by (clarsimp simp add: less_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   518
  with p1 p2 show P by auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   519
qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   520
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   521
lemma less_SucE: assumes major: "m < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   522
  and less: "m < n ==> P" and eq: "m = n ==> P" shows P
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   523
  apply (rule major [THEN lessE])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   524
  apply (rule eq, blast)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   525
  apply (rule less, blast)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   526
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   527
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   528
lemma Suc_lessE: assumes major: "Suc i < k"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   529
  and minor: "!!j. i < j ==> k = Suc j ==> P" shows P
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   530
  apply (rule major [THEN lessE])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   531
  apply (erule lessI [THEN minor])
14208
144f45277d5a misc tidying
paulson
parents: 14193
diff changeset
   532
  apply (erule Suc_lessD [THEN minor], assumption)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   533
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   534
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   535
lemma Suc_less_SucD: "Suc m < Suc n ==> m < n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   536
  by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   537
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   538
lemma less_trans_Suc:
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   539
  assumes le: "i < j" shows "j < k ==> Suc i < k"
14208
144f45277d5a misc tidying
paulson
parents: 14193
diff changeset
   540
  apply (induct k, simp_all)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   541
  apply (insert le)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   542
  apply (simp add: less_Suc_eq)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   543
  apply (blast dest: Suc_lessD)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   544
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   545
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   546
text {* Can be used with @{text less_Suc_eq} to get @{term "n = m | n < m"} *}
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   547
lemma not_less_eq: "\<not> m < n \<longleftrightarrow> n < Suc m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   548
  unfolding not_less less_Suc_eq_le ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   549
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   550
lemma not_less_eq_eq: "\<not> m \<le> n \<longleftrightarrow> Suc n \<le> m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   551
  unfolding not_le Suc_le_eq ..
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
   552
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   553
text {* Properties of "less than or equal" *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   554
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   555
lemma le_imp_less_Suc: "m \<le> n ==> m < Suc n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   556
  unfolding less_Suc_eq_le .
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   557
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   558
lemma Suc_n_not_le_n: "~ Suc n \<le> n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   559
  unfolding not_le less_Suc_eq_le ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   560
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   561
lemma le_Suc_eq: "(m \<le> Suc n) = (m \<le> n | m = Suc n)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   562
  by (simp add: less_Suc_eq_le [symmetric] less_Suc_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   563
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   564
lemma le_SucE: "m \<le> Suc n ==> (m \<le> n ==> R) ==> (m = Suc n ==> R) ==> R"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   565
  by (drule le_Suc_eq [THEN iffD1], iprover+)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   566
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   567
lemma Suc_leI: "m < n ==> Suc(m) \<le> n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   568
  unfolding Suc_le_eq .
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   569
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   570
text {* Stronger version of @{text Suc_leD} *}
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   571
lemma Suc_le_lessD: "Suc m \<le> n ==> m < n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   572
  unfolding Suc_le_eq .
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   573
26315
cb3badaa192e removed redundant less_trans, less_linear, le_imp_less_or_eq, le_less_trans, less_le_trans (cf. Orderings.thy);
wenzelm
parents: 26300
diff changeset
   574
lemma less_imp_le_nat: "m < n ==> m \<le> (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   575
  unfolding less_eq_Suc_le by (rule Suc_leD)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   576
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   577
text {* For instance, @{text "(Suc m < Suc n) = (Suc m \<le> n) = (m < n)"} *}
26315
cb3badaa192e removed redundant less_trans, less_linear, le_imp_less_or_eq, le_less_trans, less_le_trans (cf. Orderings.thy);
wenzelm
parents: 26300
diff changeset
   578
lemmas le_simps = less_imp_le_nat less_Suc_eq_le Suc_le_eq
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   579
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   580
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   581
text {* Equivalence of @{term "m \<le> n"} and @{term "m < n | m = n"} *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   582
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   583
lemma less_or_eq_imp_le: "m < n | m = n ==> m \<le> (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   584
  unfolding le_less .
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   585
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   586
lemma le_eq_less_or_eq: "(m \<le> (n::nat)) = (m < n | m=n)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   587
  by (rule le_less)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   588
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   589
text {* Useful with @{text blast}. *}
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   590
lemma eq_imp_le: "(m::nat) = n ==> m \<le> n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   591
  by auto
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   592
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   593
lemma le_refl: "n \<le> (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   594
  by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   595
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   596
lemma le_trans: "[| i \<le> j; j \<le> k |] ==> i \<le> (k::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   597
  by (rule order_trans)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   598
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   599
lemma le_anti_sym: "[| m \<le> n; n \<le> m |] ==> m = (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   600
  by (rule antisym)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   601
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   602
lemma nat_less_le: "((m::nat) < n) = (m \<le> n & m \<noteq> n)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   603
  by (rule less_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   604
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   605
lemma le_neq_implies_less: "(m::nat) \<le> n ==> m \<noteq> n ==> m < n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   606
  unfolding less_le ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   607
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   608
lemma nat_le_linear: "(m::nat) \<le> n | n \<le> m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   609
  by (rule linear)
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   610
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   611
lemmas linorder_neqE_nat = linorder_neqE [where 'a = nat]
15921
b6e345548913 Fixing a problem with lin.arith.
nipkow
parents: 15539
diff changeset
   612
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   613
lemma le_less_Suc_eq: "m \<le> n ==> (n < Suc m) = (n = m)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   614
  unfolding less_Suc_eq_le by auto
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   615
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   616
lemma not_less_less_Suc_eq: "~ n < m ==> (n < Suc m) = (n = m)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   617
  unfolding not_less by (rule le_less_Suc_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   618
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   619
lemmas not_less_simps = not_less_less_Suc_eq le_less_Suc_eq
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   620
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   621
text {* These two rules ease the use of primitive recursion.
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   622
NOTE USE OF @{text "=="} *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   623
lemma def_nat_rec_0: "(!!n. f n == nat_rec c h n) ==> f 0 = c"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   624
by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   625
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   626
lemma def_nat_rec_Suc: "(!!n. f n == nat_rec c h n) ==> f (Suc n) = h n (f n)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   627
by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   628
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   629
lemma not0_implies_Suc: "n \<noteq> 0 ==> \<exists>m. n = Suc m"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   630
by (cases n) simp_all
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   631
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   632
lemma gr0_implies_Suc: "n > 0 ==> \<exists>m. n = Suc m"
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   633
by (cases n) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   634
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   635
lemma gr_implies_not0: fixes n :: nat shows "m<n ==> n \<noteq> 0"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   636
by (cases n) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   637
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   638
lemma neq0_conv[iff]: fixes n :: nat shows "(n \<noteq> 0) = (0 < n)"
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   639
by (cases n) simp_all
25140
273772abbea2 More changes from >0 to ~=0::nat
nipkow
parents: 25134
diff changeset
   640
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   641
text {* This theorem is useful with @{text blast} *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   642
lemma gr0I: "((n::nat) = 0 ==> False) ==> 0 < n"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   643
by (rule neq0_conv[THEN iffD1], iprover)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   644
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   645
lemma gr0_conv_Suc: "(0 < n) = (\<exists>m. n = Suc m)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   646
by (fast intro: not0_implies_Suc)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   647
24286
7619080e49f0 ATP blacklisting is now in theory data, attribute noatp
paulson
parents: 24196
diff changeset
   648
lemma not_gr0 [iff,noatp]: "!!n::nat. (~ (0 < n)) = (n = 0)"
25134
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   649
using neq0_conv by blast
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   650
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   651
lemma Suc_le_D: "(Suc n \<le> m') ==> (? m. m' = Suc m)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   652
by (induct m') simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   653
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   654
text {* Useful in certain inductive arguments *}
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   655
lemma less_Suc_eq_0_disj: "(m < Suc n) = (m = 0 | (\<exists>j. m = Suc j & j < n))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   656
by (cases m) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   657
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   658
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   659
subsubsection {* @{term min} and @{term max} *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   660
25076
a50b36401c61 localized mono predicate
haftmann
parents: 25062
diff changeset
   661
lemma mono_Suc: "mono Suc"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   662
by (rule monoI) simp
25076
a50b36401c61 localized mono predicate
haftmann
parents: 25062
diff changeset
   663
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   664
lemma min_0L [simp]: "min 0 n = (0::nat)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   665
by (rule min_leastL) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   666
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   667
lemma min_0R [simp]: "min n 0 = (0::nat)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   668
by (rule min_leastR) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   669
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   670
lemma min_Suc_Suc [simp]: "min (Suc m) (Suc n) = Suc (min m n)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   671
by (simp add: mono_Suc min_of_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   672
22191
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   673
lemma min_Suc1:
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   674
   "min (Suc n) m = (case m of 0 => 0 | Suc m' => Suc(min n m'))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   675
by (simp split: nat.split)
22191
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   676
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   677
lemma min_Suc2:
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   678
   "min m (Suc n) = (case m of 0 => 0 | Suc m' => Suc(min m' n))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   679
by (simp split: nat.split)
22191
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   680
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   681
lemma max_0L [simp]: "max 0 n = (n::nat)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   682
by (rule max_leastL) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   683
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   684
lemma max_0R [simp]: "max n 0 = (n::nat)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   685
by (rule max_leastR) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   686
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   687
lemma max_Suc_Suc [simp]: "max (Suc m) (Suc n) = Suc(max m n)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   688
by (simp add: mono_Suc max_of_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   689
22191
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   690
lemma max_Suc1:
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   691
   "max (Suc n) m = (case m of 0 => Suc n | Suc m' => Suc(max n m'))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   692
by (simp split: nat.split)
22191
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   693
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   694
lemma max_Suc2:
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   695
   "max m (Suc n) = (case m of 0 => Suc n | Suc m' => Suc(max m' n))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   696
by (simp split: nat.split)
22191
9c07aab3a653 min/max lemmas (actually unused!)
paulson
parents: 22157
diff changeset
   697
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   698
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   699
subsubsection {* Monotonicity of Addition *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   700
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   701
lemma Suc_pred [simp]: "n>0 ==> Suc (n - Suc 0) = n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   702
by (simp add: diff_Suc split: nat.split)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   703
30128
365ee7319b86 revert some Suc 0 lemmas back to their original forms; added some simp rules for (1::nat)
huffman
parents: 30093
diff changeset
   704
lemma Suc_diff_1 [simp]: "0 < n ==> Suc (n - 1) = n"
365ee7319b86 revert some Suc 0 lemmas back to their original forms; added some simp rules for (1::nat)
huffman
parents: 30093
diff changeset
   705
unfolding One_nat_def by (rule Suc_pred)
365ee7319b86 revert some Suc 0 lemmas back to their original forms; added some simp rules for (1::nat)
huffman
parents: 30093
diff changeset
   706
14331
8dbbb7cf3637 re-organized numeric lemmas
paulson
parents: 14302
diff changeset
   707
lemma nat_add_left_cancel_le [simp]: "(k + m \<le> k + n) = (m\<le>(n::nat))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   708
by (induct k) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   709
14331
8dbbb7cf3637 re-organized numeric lemmas
paulson
parents: 14302
diff changeset
   710
lemma nat_add_left_cancel_less [simp]: "(k + m < k + n) = (m<(n::nat))"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   711
by (induct k) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   712
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   713
lemma add_gr_0 [iff]: "!!m::nat. (m + n > 0) = (m>0 | n>0)"
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   714
by(auto dest:gr0_implies_Suc)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   715
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   716
text {* strict, in 1st argument *}
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   717
lemma add_less_mono1: "i < j ==> i + k < j + (k::nat)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   718
by (induct k) simp_all
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   719
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   720
text {* strict, in both arguments *}
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   721
lemma add_less_mono: "[|i < j; k < l|] ==> i + k < j + (l::nat)"
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   722
  apply (rule add_less_mono1 [THEN less_trans], assumption+)
15251
bb6f072c8d10 converted some induct_tac to induct
paulson
parents: 15140
diff changeset
   723
  apply (induct j, simp_all)
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   724
  done
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   725
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   726
text {* Deleted @{text less_natE}; use @{text "less_imp_Suc_add RS exE"} *}
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   727
lemma less_imp_Suc_add: "m < n ==> (\<exists>k. n = Suc (m + k))"
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   728
  apply (induct n)
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   729
  apply (simp_all add: order_le_less)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   730
  apply (blast elim!: less_SucE
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   731
               intro!: add_0_right [symmetric] add_Suc_right [symmetric])
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   732
  done
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   733
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   734
text {* strict, in 1st argument; proof is by induction on @{text "k > 0"} *}
25134
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   735
lemma mult_less_mono2: "(i::nat) < j ==> 0<k ==> k * i < k * j"
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   736
apply(auto simp: gr0_conv_Suc)
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   737
apply (induct_tac m)
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   738
apply (simp_all add: add_less_mono)
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   739
done
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   740
14740
c8e1937110c2 fixed latex problems
nipkow
parents: 14738
diff changeset
   741
text{*The naturals form an ordered @{text comm_semiring_1_cancel}*}
14738
83f1a514dcb4 changes made due to new Ring_and_Field theory
obua
parents: 14691
diff changeset
   742
instance nat :: ordered_semidom
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   743
proof
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   744
  fix i j k :: nat
14348
744c868ee0b7 Defining the type class "ringpower" and deleting superseded theorems for
paulson
parents: 14341
diff changeset
   745
  show "0 < (1::nat)" by simp
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   746
  show "i \<le> j ==> k + i \<le> k + j" by simp
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   747
  show "i < j ==> 0 < k ==> k * i < k * j" by (simp add: mult_less_mono2)
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   748
qed
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   749
30056
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   750
instance nat :: no_zero_divisors
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   751
proof
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   752
  fix a::nat and b::nat show "a ~= 0 \<Longrightarrow> b ~= 0 \<Longrightarrow> a * b ~= 0" by auto
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   753
qed
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   754
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   755
lemma nat_mult_1: "(1::nat) * n = n"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   756
by simp
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   757
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   758
lemma nat_mult_1_right: "n * (1::nat) = n"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   759
by simp
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   760
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   761
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   762
subsubsection {* Additional theorems about @{term "op \<le>"} *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   763
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   764
text {* Complete induction, aka course-of-values induction *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   765
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   766
instance nat :: wellorder proof
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   767
  fix P and n :: nat
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   768
  assume step: "\<And>n::nat. (\<And>m. m < n \<Longrightarrow> P m) \<Longrightarrow> P n"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   769
  have "\<And>q. q \<le> n \<Longrightarrow> P q"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   770
  proof (induct n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   771
    case (0 n)
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   772
    have "P 0" by (rule step) auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   773
    thus ?case using 0 by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   774
  next
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   775
    case (Suc m n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   776
    then have "n \<le> m \<or> n = Suc m" by (simp add: le_Suc_eq)
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   777
    thus ?case
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   778
    proof
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   779
      assume "n \<le> m" thus "P n" by (rule Suc(1))
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   780
    next
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   781
      assume n: "n = Suc m"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   782
      show "P n"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   783
        by (rule step) (rule Suc(1), simp add: n le_simps)
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   784
    qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   785
  qed
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   786
  then show "P n" by auto
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   787
qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   788
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   789
lemma Least_Suc:
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   790
     "[| P n; ~ P 0 |] ==> (LEAST n. P n) = Suc (LEAST m. P(Suc m))"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   791
  apply (case_tac "n", auto)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   792
  apply (frule LeastI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   793
  apply (drule_tac P = "%x. P (Suc x) " in LeastI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   794
  apply (subgoal_tac " (LEAST x. P x) \<le> Suc (LEAST x. P (Suc x))")
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   795
  apply (erule_tac [2] Least_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   796
  apply (case_tac "LEAST x. P x", auto)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   797
  apply (drule_tac P = "%x. P (Suc x) " in Least_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   798
  apply (blast intro: order_antisym)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   799
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   800
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   801
lemma Least_Suc2:
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   802
   "[|P n; Q m; ~P 0; !k. P (Suc k) = Q k|] ==> Least P = Suc (Least Q)"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   803
  apply (erule (1) Least_Suc [THEN ssubst])
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   804
  apply simp
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   805
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   806
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   807
lemma ex_least_nat_le: "\<not>P(0) \<Longrightarrow> P(n::nat) \<Longrightarrow> \<exists>k\<le>n. (\<forall>i<k. \<not>P i) & P(k)"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   808
  apply (cases n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   809
   apply blast
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   810
  apply (rule_tac x="LEAST k. P(k)" in exI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   811
  apply (blast intro: Least_le dest: not_less_Least intro: LeastI_ex)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   812
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   813
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   814
lemma ex_least_nat_less: "\<not>P(0) \<Longrightarrow> P(n::nat) \<Longrightarrow> \<exists>k<n. (\<forall>i\<le>k. \<not>P i) & P(k+1)"
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
   815
  unfolding One_nat_def
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   816
  apply (cases n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   817
   apply blast
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   818
  apply (frule (1) ex_least_nat_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   819
  apply (erule exE)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   820
  apply (case_tac k)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   821
   apply simp
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   822
  apply (rename_tac k1)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   823
  apply (rule_tac x=k1 in exI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   824
  apply (auto simp add: less_eq_Suc_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   825
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   826
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   827
lemma nat_less_induct:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   828
  assumes "!!n. \<forall>m::nat. m < n --> P m ==> P n" shows "P n"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   829
  using assms less_induct by blast
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   830
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   831
lemma measure_induct_rule [case_names less]:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   832
  fixes f :: "'a \<Rightarrow> nat"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   833
  assumes step: "\<And>x. (\<And>y. f y < f x \<Longrightarrow> P y) \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   834
  shows "P a"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   835
by (induct m\<equiv>"f a" arbitrary: a rule: less_induct) (auto intro: step)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   836
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   837
text {* old style induction rules: *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   838
lemma measure_induct:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   839
  fixes f :: "'a \<Rightarrow> nat"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   840
  shows "(\<And>x. \<forall>y. f y < f x \<longrightarrow> P y \<Longrightarrow> P x) \<Longrightarrow> P a"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   841
  by (rule measure_induct_rule [of f P a]) iprover
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   842
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   843
lemma full_nat_induct:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   844
  assumes step: "(!!n. (ALL m. Suc m <= n --> P m) ==> P n)"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   845
  shows "P n"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   846
  by (rule less_induct) (auto intro: step simp:le_simps)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   847
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   848
text{*An induction rule for estabilishing binary relations*}
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   849
lemma less_Suc_induct:
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   850
  assumes less:  "i < j"
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   851
     and  step:  "!!i. P i (Suc i)"
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   852
     and  trans: "!!i j k. P i j ==> P j k ==> P i k"
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   853
  shows "P i j"
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   854
proof -
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   855
  from less obtain k where j: "j = Suc(i+k)" by (auto dest: less_imp_Suc_add)
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   856
  have "P i (Suc (i + k))"
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   857
  proof (induct k)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   858
    case 0
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   859
    show ?case by (simp add: step)
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   860
  next
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   861
    case (Suc k)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   862
    thus ?case by (auto intro: assms)
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   863
  qed
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   864
  thus "P i j" by (simp add: j)
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   865
qed
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   866
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   867
text {* The method of infinite descent, frequently used in number theory.
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   868
Provided by Roelof Oosterhuis.
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   869
$P(n)$ is true for all $n\in\mathbb{N}$ if
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   870
\begin{itemize}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   871
  \item case ``0'': given $n=0$ prove $P(n)$,
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   872
  \item case ``smaller'': given $n>0$ and $\neg P(n)$ prove there exists
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   873
        a smaller integer $m$ such that $\neg P(m)$.
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   874
\end{itemize} *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   875
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   876
text{* A compact version without explicit base case: *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   877
lemma infinite_descent:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   878
  "\<lbrakk> !!n::nat. \<not> P n \<Longrightarrow>  \<exists>m<n. \<not>  P m \<rbrakk> \<Longrightarrow>  P n"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   879
by (induct n rule: less_induct, auto)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   880
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   881
lemma infinite_descent0[case_names 0 smaller]: 
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   882
  "\<lbrakk> P 0; !!n. n>0 \<Longrightarrow> \<not> P n \<Longrightarrow> (\<exists>m::nat. m < n \<and> \<not>P m) \<rbrakk> \<Longrightarrow> P n"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   883
by (rule infinite_descent) (case_tac "n>0", auto)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   884
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   885
text {*
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   886
Infinite descent using a mapping to $\mathbb{N}$:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   887
$P(x)$ is true for all $x\in D$ if there exists a $V: D \to \mathbb{N}$ and
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   888
\begin{itemize}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   889
\item case ``0'': given $V(x)=0$ prove $P(x)$,
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   890
\item case ``smaller'': given $V(x)>0$ and $\neg P(x)$ prove there exists a $y \in D$ such that $V(y)<V(x)$ and $~\neg P(y)$.
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   891
\end{itemize}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   892
NB: the proof also shows how to use the previous lemma. *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   893
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   894
corollary infinite_descent0_measure [case_names 0 smaller]:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   895
  assumes A0: "!!x. V x = (0::nat) \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   896
    and   A1: "!!x. V x > 0 \<Longrightarrow> \<not>P x \<Longrightarrow> (\<exists>y. V y < V x \<and> \<not>P y)"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   897
  shows "P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   898
proof -
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   899
  obtain n where "n = V x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   900
  moreover have "\<And>x. V x = n \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   901
  proof (induct n rule: infinite_descent0)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   902
    case 0 -- "i.e. $V(x) = 0$"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   903
    with A0 show "P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   904
  next -- "now $n>0$ and $P(x)$ does not hold for some $x$ with $V(x)=n$"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   905
    case (smaller n)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   906
    then obtain x where vxn: "V x = n " and "V x > 0 \<and> \<not> P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   907
    with A1 obtain y where "V y < V x \<and> \<not> P y" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   908
    with vxn obtain m where "m = V y \<and> m<n \<and> \<not> P y" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   909
    then show ?case by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   910
  qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   911
  ultimately show "P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   912
qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   913
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   914
text{* Again, without explicit base case: *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   915
lemma infinite_descent_measure:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   916
assumes "!!x. \<not> P x \<Longrightarrow> \<exists>y. (V::'a\<Rightarrow>nat) y < V x \<and> \<not> P y" shows "P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   917
proof -
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   918
  from assms obtain n where "n = V x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   919
  moreover have "!!x. V x = n \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   920
  proof (induct n rule: infinite_descent, auto)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   921
    fix x assume "\<not> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   922
    with assms show "\<exists>m < V x. \<exists>y. V y = m \<and> \<not> P y" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   923
  qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   924
  ultimately show "P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   925
qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   926
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   927
text {* A [clumsy] way of lifting @{text "<"}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   928
  monotonicity to @{text "\<le>"} monotonicity *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   929
lemma less_mono_imp_le_mono:
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   930
  "\<lbrakk> !!i j::nat. i < j \<Longrightarrow> f i < f j; i \<le> j \<rbrakk> \<Longrightarrow> f i \<le> ((f j)::nat)"
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   931
by (simp add: order_le_less) (blast)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   932
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   933
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   934
text {* non-strict, in 1st argument *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   935
lemma add_le_mono1: "i \<le> j ==> i + k \<le> j + (k::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   936
by (rule add_right_mono)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   937
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   938
text {* non-strict, in both arguments *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   939
lemma add_le_mono: "[| i \<le> j;  k \<le> l |] ==> i + k \<le> j + (l::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   940
by (rule add_mono)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   941
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   942
lemma le_add2: "n \<le> ((m + n)::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   943
by (insert add_right_mono [of 0 m n], simp)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   944
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   945
lemma le_add1: "n \<le> ((n + m)::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   946
by (simp add: add_commute, rule le_add2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   947
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   948
lemma less_add_Suc1: "i < Suc (i + m)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   949
by (rule le_less_trans, rule le_add1, rule lessI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   950
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   951
lemma less_add_Suc2: "i < Suc (m + i)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   952
by (rule le_less_trans, rule le_add2, rule lessI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   953
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   954
lemma less_iff_Suc_add: "(m < n) = (\<exists>k. n = Suc (m + k))"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   955
by (iprover intro!: less_add_Suc1 less_imp_Suc_add)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   956
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   957
lemma trans_le_add1: "(i::nat) \<le> j ==> i \<le> j + m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   958
by (rule le_trans, assumption, rule le_add1)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   959
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   960
lemma trans_le_add2: "(i::nat) \<le> j ==> i \<le> m + j"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   961
by (rule le_trans, assumption, rule le_add2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   962
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   963
lemma trans_less_add1: "(i::nat) < j ==> i < j + m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   964
by (rule less_le_trans, assumption, rule le_add1)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   965
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   966
lemma trans_less_add2: "(i::nat) < j ==> i < m + j"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   967
by (rule less_le_trans, assumption, rule le_add2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   968
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   969
lemma add_lessD1: "i + j < (k::nat) ==> i < k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   970
apply (rule le_less_trans [of _ "i+j"])
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   971
apply (simp_all add: le_add1)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   972
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   973
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   974
lemma not_add_less1 [iff]: "~ (i + j < (i::nat))"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   975
apply (rule notI)
26335
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   976
apply (drule add_lessD1)
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   977
apply (erule less_irrefl [THEN notE])
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   978
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   979
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   980
lemma not_add_less2 [iff]: "~ (j + i < (i::nat))"
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   981
by (simp add: add_commute)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   982
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   983
lemma add_leD1: "m + k \<le> n ==> m \<le> (n::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   984
apply (rule order_trans [of _ "m+k"])
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   985
apply (simp_all add: le_add1)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   986
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   987
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   988
lemma add_leD2: "m + k \<le> n ==> k \<le> (n::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   989
apply (simp add: add_commute)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   990
apply (erule add_leD1)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   991
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   992
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   993
lemma add_leE: "(m::nat) + k \<le> n ==> (m \<le> n ==> k \<le> n ==> R) ==> R"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   994
by (blast dest: add_leD1 add_leD2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   995
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   996
text {* needs @{text "!!k"} for @{text add_ac} to work *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   997
lemma less_add_eq_less: "!!k::nat. k < l ==> m + l = k + n ==> m < n"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   998
by (force simp del: add_Suc_right
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   999
    simp add: less_iff_Suc_add add_Suc_right [symmetric] add_ac)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1000
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1001
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1002
subsubsection {* More results about difference *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1003
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1004
text {* Addition is the inverse of subtraction:
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1005
  if @{term "n \<le> m"} then @{term "n + (m - n) = m"}. *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1006
lemma add_diff_inverse: "~  m < n ==> n + (m - n) = (m::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1007
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1008
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1009
lemma le_add_diff_inverse [simp]: "n \<le> m ==> n + (m - n) = (m::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1010
by (simp add: add_diff_inverse linorder_not_less)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1011
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1012
lemma le_add_diff_inverse2 [simp]: "n \<le> m ==> (m - n) + n = (m::nat)"
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
  1013
by (simp add: add_commute)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1014
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1015
lemma Suc_diff_le: "n \<le> m ==> Suc m - n = Suc (m - n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1016
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1017
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1018
lemma diff_less_Suc: "m - n < Suc m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1019
apply (induct m n rule: diff_induct)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1020
apply (erule_tac [3] less_SucE)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1021
apply (simp_all add: less_Suc_eq)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1022
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1023
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1024
lemma diff_le_self [simp]: "m - n \<le> (m::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1025
by (induct m n rule: diff_induct) (simp_all add: le_SucI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1026
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1027
lemma le_iff_add: "(m::nat) \<le> n = (\<exists>k. n = m + k)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1028
  by (auto simp: le_add1 dest!: le_add_diff_inverse sym [of _ n])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1029
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1030
lemma less_imp_diff_less: "(j::nat) < k ==> j - n < k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1031
by (rule le_less_trans, rule diff_le_self)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1032
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1033
lemma diff_Suc_less [simp]: "0<n ==> n - Suc i < n"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1034
by (cases n) (auto simp add: le_simps)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1035
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1036
lemma diff_add_assoc: "k \<le> (j::nat) ==> (i + j) - k = i + (j - k)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1037
by (induct j k rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1038
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1039
lemma diff_add_assoc2: "k \<le> (j::nat) ==> (j + i) - k = (j - k) + i"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1040
by (simp add: add_commute diff_add_assoc)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1041
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1042
lemma le_imp_diff_is_add: "i \<le> (j::nat) ==> (j - i = k) = (j = k + i)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1043
by (auto simp add: diff_add_inverse2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1044
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1045
lemma diff_is_0_eq [simp]: "((m::nat) - n = 0) = (m \<le> n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1046
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1047
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1048
lemma diff_is_0_eq' [simp]: "m \<le> n ==> (m::nat) - n = 0"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1049
by (rule iffD2, rule diff_is_0_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1050
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1051
lemma zero_less_diff [simp]: "(0 < n - (m::nat)) = (m < n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1052
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1053
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1054
lemma less_imp_add_positive:
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1055
  assumes "i < j"
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1056
  shows "\<exists>k::nat. 0 < k & i + k = j"
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1057
proof
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1058
  from assms show "0 < j - i & i + (j - i) = j"
23476
839db6346cc8 fix looping simp rule
huffman
parents: 23438
diff changeset
  1059
    by (simp add: order_less_imp_le)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1060
qed
9436
62bb04ab4b01 rearranged setup of arithmetic procedures, avoiding global reference values;
wenzelm
parents: 7702
diff changeset
  1061
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1062
text {* a nice rewrite for bounded subtraction *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1063
lemma nat_minus_add_max:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1064
  fixes n m :: nat
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1065
  shows "n - m + m = max n m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1066
    by (simp add: max_def not_le order_less_imp_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1067
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1068
lemma nat_diff_split:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1069
  "P(a - b::nat) = ((a<b --> P 0) & (ALL d. a = b + d --> P d))"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1070
    -- {* elimination of @{text -} on @{text nat} *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1071
by (cases "a < b")
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1072
  (auto simp add: diff_is_0_eq [THEN iffD2] diff_add_inverse
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1073
    not_less le_less dest!: sym [of a] sym [of b] add_eq_self_zero)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1074
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1075
lemma nat_diff_split_asm:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1076
  "P(a - b::nat) = (~ (a < b & ~ P 0 | (EX d. a = b + d & ~ P d)))"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1077
    -- {* elimination of @{text -} on @{text nat} in assumptions *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1078
by (auto split: nat_diff_split)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1079
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1080
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1081
subsubsection {* Monotonicity of Multiplication *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1082
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1083
lemma mult_le_mono1: "i \<le> (j::nat) ==> i * k \<le> j * k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1084
by (simp add: mult_right_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1085
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1086
lemma mult_le_mono2: "i \<le> (j::nat) ==> k * i \<le> k * j"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1087
by (simp add: mult_left_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1088
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1089
text {* @{text "\<le>"} monotonicity, BOTH arguments *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1090
lemma mult_le_mono: "i \<le> (j::nat) ==> k \<le> l ==> i * k \<le> j * l"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1091
by (simp add: mult_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1092
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1093
lemma mult_less_mono1: "(i::nat) < j ==> 0 < k ==> i * k < j * k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1094
by (simp add: mult_strict_right_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1095
14266
08b34c902618 conversion of integers to use Ring_and_Field;
paulson
parents: 14265
diff changeset
  1096
text{*Differs from the standard @{text zero_less_mult_iff} in that
08b34c902618 conversion of integers to use Ring_and_Field;
paulson
parents: 14265
diff changeset
  1097
      there are no negative numbers.*}
08b34c902618 conversion of integers to use Ring_and_Field;
paulson
parents: 14265
diff changeset
  1098
lemma nat_0_less_mult_iff [simp]: "(0 < (m::nat) * n) = (0 < m & 0 < n)"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1099
  apply (induct m)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1100
   apply simp
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1101
  apply (case_tac n)
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1102
   apply simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1103
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1104
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
  1105
lemma one_le_mult_iff [simp]: "(Suc 0 \<le> m * n) = (Suc 0 \<le> m & Suc 0 \<le> n)"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1106
  apply (induct m)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1107
   apply simp
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1108
  apply (case_tac n)
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1109
   apply simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1110
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1111
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
  1112
lemma mult_less_cancel2 [simp]: "((m::nat) * k < n * k) = (0 < k & m < n)"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1113
  apply (safe intro!: mult_less_mono1)
14208
144f45277d5a misc tidying
paulson
parents: 14193
diff changeset
  1114
  apply (case_tac k, auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1115
  apply (simp del: le_0_eq add: linorder_not_le [symmetric])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1116
  apply (blast intro: mult_le_mono1)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1117
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1118
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1119
lemma mult_less_cancel1 [simp]: "(k * (m::nat) < k * n) = (0 < k & m < n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1120
by (simp add: mult_commute [of k])
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1121
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1122
lemma mult_le_cancel1 [simp]: "(k * (m::nat) \<le> k * n) = (0 < k --> m \<le> n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1123
by (simp add: linorder_not_less [symmetric], auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1124
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1125
lemma mult_le_cancel2 [simp]: "((m::nat) * k \<le> n * k) = (0 < k --> m \<le> n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1126
by (simp add: linorder_not_less [symmetric], auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1127
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1128
lemma Suc_mult_less_cancel1: "(Suc k * m < Suc k * n) = (m < n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1129
by (subst mult_less_cancel1) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1130
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1131
lemma Suc_mult_le_cancel1: "(Suc k * m \<le> Suc k * n) = (m \<le> n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1132
by (subst mult_le_cancel1) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1133
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1134
lemma le_square: "m \<le> m * (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1135
  by (cases m) (auto intro: le_add1)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1136
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1137
lemma le_cube: "(m::nat) \<le> m * (m * m)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1138
  by (cases m) (auto intro: le_add1)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1139
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1140
text {* Lemma for @{text gcd} *}
30128
365ee7319b86 revert some Suc 0 lemmas back to their original forms; added some simp rules for (1::nat)
huffman
parents: 30093
diff changeset
  1141
lemma mult_eq_self_implies_10: "(m::nat) = m * n ==> n = 1 | m = 0"
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1142
  apply (drule sym)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1143
  apply (rule disjCI)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1144
  apply (rule nat_less_cases, erule_tac [2] _)
25157
8b80535cd017 random tidying of proofs
paulson
parents: 25145
diff changeset
  1145
   apply (drule_tac [2] mult_less_mono2)
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
  1146
    apply (auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1147
  done
9436
62bb04ab4b01 rearranged setup of arithmetic procedures, avoiding global reference values;
wenzelm
parents: 7702
diff changeset
  1148
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1149
text {* the lattice order on @{typ nat} *}
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1150
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1151
instantiation nat :: distrib_lattice
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1152
begin
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1153
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1154
definition
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1155
  "(inf \<Colon> nat \<Rightarrow> nat \<Rightarrow> nat) = min"
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1156
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1157
definition
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1158
  "(sup \<Colon> nat \<Rightarrow> nat \<Rightarrow> nat) = max"
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1159
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1160
instance by intro_classes
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1161
  (auto simp add: inf_nat_def sup_nat_def max_def not_le min_def
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1162
    intro: order_less_imp_le antisym elim!: order_trans order_less_trans)
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1163
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1164
end
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1165
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1166
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1167
subsection {* Natural operation of natural numbers on functions *}
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1168
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1169
text {*
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1170
  We use the same logical constant for the power operations on
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1171
  functions and relations, in order to share the same syntax.
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1172
*}
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1173
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1174
consts compow :: "nat \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> ('a \<Rightarrow> 'b)"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1175
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1176
abbreviation compower :: "('a \<Rightarrow> 'b) \<Rightarrow> nat \<Rightarrow> 'a \<Rightarrow> 'b" (infixr "^^" 80) where
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1177
  "f ^^ n \<equiv> compow n f"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1178
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1179
notation (latex output)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1180
  compower ("(_\<^bsup>_\<^esup>)" [1000] 1000)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1181
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1182
notation (HTML output)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1183
  compower ("(_\<^bsup>_\<^esup>)" [1000] 1000)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1184
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1185
text {* @{text "f ^^ n = f o ... o f"}, the n-fold composition of @{text f} *}
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1186
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1187
overloading
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1188
  funpow == "compow :: nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> ('a \<Rightarrow> 'a)"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1189
begin
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1190
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1191
primrec funpow :: "nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'a" where
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1192
    "funpow 0 f = id"
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1193
  | "funpow (Suc n) f = f o funpow n f"
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1194
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1195
end
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1196
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1197
text {* for code generation *}
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1198
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1199
definition funpow :: "nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'a" where
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1200
  funpow_code_def [code post]: "funpow = compow"
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1201
31155
92d8ff6af82c monomorphic code generation for power operations
haftmann
parents: 31100
diff changeset
  1202
lemmas [code unfold] = funpow_code_def [symmetric]
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1203
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1204
lemma [code]:
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1205
  "funpow 0 f = id"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1206
  "funpow (Suc n) f = f o funpow n f"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1207
  unfolding funpow_code_def by simp_all
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1208
30975
b2fa60d56735 some jokes are just too bad to appear in a theory file
haftmann
parents: 30971
diff changeset
  1209
hide (open) const funpow
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1210
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1211
lemma funpow_add:
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1212
  "f ^^ (m + n) = f ^^ m \<circ> f ^^ n"
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1213
  by (induct m) simp_all
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1214
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1215
lemma funpow_swap1:
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1216
  "f ((f ^^ n) x) = (f ^^ n) (f x)"
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1217
proof -
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1218
  have "f ((f ^^ n) x) = (f ^^ (n + 1)) x" by simp
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1219
  also have "\<dots>  = (f ^^ n o f ^^ 1) x" by (simp only: funpow_add)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1220
  also have "\<dots> = (f ^^ n) (f x)" by simp
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1221
  finally show ?thesis .
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1222
qed
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1223
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1224
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1225
subsection {* Embedding of the Naturals into any
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1226
  @{text semiring_1}: @{term of_nat} *}
24196
f1dbfd7e3223 localized of_nat
haftmann
parents: 24162
diff changeset
  1227
f1dbfd7e3223 localized of_nat
haftmann
parents: 24162
diff changeset
  1228
context semiring_1
f1dbfd7e3223 localized of_nat
haftmann
parents: 24162
diff changeset
  1229
begin
f1dbfd7e3223 localized of_nat
haftmann
parents: 24162
diff changeset
  1230
25559
f14305fb698c authentic primrec
haftmann
parents: 25534
diff changeset
  1231
primrec
f14305fb698c authentic primrec
haftmann
parents: 25534
diff changeset
  1232
  of_nat :: "nat \<Rightarrow> 'a"
f14305fb698c authentic primrec
haftmann
parents: 25534
diff changeset
  1233
where
f14305fb698c authentic primrec
haftmann
parents: 25534
diff changeset
  1234
  of_nat_0:     "of_nat 0 = 0"
f14305fb698c authentic primrec
haftmann
parents: 25534
diff changeset
  1235
  | of_nat_Suc: "of_nat (Suc m) = 1 + of_nat m"
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1236
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1237
lemma of_nat_1 [simp]: "of_nat 1 = 1"
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
  1238
  unfolding One_nat_def by simp
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1239
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1240
lemma of_nat_add [simp]: "of_nat (m + n) = of_nat m + of_nat n"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1241
  by (induct m) (simp_all add: add_ac)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1242
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1243
lemma of_nat_mult: "of_nat (m * n) = of_nat m * of_nat n"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1244
  by (induct m) (simp_all add: add_ac left_distrib)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1245
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1246
primrec of_nat_aux :: "('a \<Rightarrow> 'a) \<Rightarrow> nat \<Rightarrow> 'a \<Rightarrow> 'a" where
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1247
  "of_nat_aux inc 0 i = i"
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1248
  | "of_nat_aux inc (Suc n) i = of_nat_aux inc n (inc i)" -- {* tail recursive *}
25928
042e877d9841 tuned code setup
haftmann
parents: 25690
diff changeset
  1249
30966
55104c664185 avoid local [code]
haftmann
parents: 30954
diff changeset
  1250
lemma of_nat_code:
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1251
  "of_nat n = of_nat_aux (\<lambda>i. i + 1) n 0"
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1252
proof (induct n)
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1253
  case 0 then show ?case by simp
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1254
next
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1255
  case (Suc n)
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1256
  have "\<And>i. of_nat_aux (\<lambda>i. i + 1) n (i + 1) = of_nat_aux (\<lambda>i. i + 1) n i + 1"
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1257
    by (induct n) simp_all
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1258
  from this [of 0] have "of_nat_aux (\<lambda>i. i + 1) n 1 = of_nat_aux (\<lambda>i. i + 1) n 0 + 1"
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1259
    by simp
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1260
  with Suc show ?case by (simp add: add_commute)
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
  1261
qed
30966
55104c664185 avoid local [code]
haftmann
parents: 30954
diff changeset
  1262
24196
f1dbfd7e3223 localized of_nat
haftmann
parents: 24162
diff changeset
  1263
end
f1dbfd7e3223 localized of_nat
haftmann
parents: 24162
diff changeset
  1264
30966
55104c664185 avoid local [code]
haftmann
parents: 30954
diff changeset
  1265
declare of_nat_code [code, code unfold, code inline del]
55104c664185 avoid local [code]
haftmann
parents: 30954
diff changeset
  1266
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1267
text{*Class for unital semirings with characteristic zero.
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1268
 Includes non-ordered rings like the complex numbers.*}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1269
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1270
class semiring_char_0 = semiring_1 +
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1271
  assumes of_nat_eq_iff [simp]: "of_nat m = of_nat n \<longleftrightarrow> m = n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1272
begin
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1273
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1274
text{*Special cases where either operand is zero*}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1275
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1276
lemma of_nat_0_eq_iff [simp, noatp]: "0 = of_nat n \<longleftrightarrow> 0 = n"
31024
0fdf666e08bf reimplement reorientation simproc using theory data
huffman
parents: 30975
diff changeset
  1277
  by (rule of_nat_eq_iff [of 0 n, unfolded of_nat_0])
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1278
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1279
lemma of_nat_eq_0_iff [simp, noatp]: "of_nat m = 0 \<longleftrightarrow> m = 0"
31024
0fdf666e08bf reimplement reorientation simproc using theory data
huffman
parents: 30975
diff changeset
  1280
  by (rule of_nat_eq_iff [of m 0, unfolded of_nat_0])
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1281
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1282
lemma inj_of_nat: "inj of_nat"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1283
  by (simp add: inj_on_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1284
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1285
end
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1286
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1287
context ordered_semidom
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1288
begin
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1289
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1290
lemma zero_le_imp_of_nat: "0 \<le> of_nat m"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1291
  apply (induct m, simp_all)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1292
  apply (erule order_trans)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1293
  apply (rule ord_le_eq_trans [OF _ add_commute])
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1294
  apply (rule less_add_one [THEN less_imp_le])
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1295
  done
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1296
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1297
lemma less_imp_of_nat_less: "m < n \<Longrightarrow> of_nat m < of_nat n"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1298
  apply (induct m n rule: diff_induct, simp_all)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1299
  apply (insert add_less_le_mono [OF zero_less_one zero_le_imp_of_nat], force)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1300
  done
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1301
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1302
lemma of_nat_less_imp_less: "of_nat m < of_nat n \<Longrightarrow> m < n"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1303
  apply (induct m n rule: diff_induct, simp_all)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1304
  apply (insert zero_le_imp_of_nat)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1305
  apply (force simp add: not_less [symmetric])
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1306
  done
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1307
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1308
lemma of_nat_less_iff [simp]: "of_nat m < of_nat n \<longleftrightarrow> m < n"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1309
  by (blast intro: of_nat_less_imp_less less_imp_of_nat_less)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1310
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1311
lemma of_nat_le_iff [simp]: "of_nat m \<le> of_nat n \<longleftrightarrow> m \<le> n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1312
  by (simp add: not_less [symmetric] linorder_not_less [symmetric])
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1313
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1314
text{*Every @{text ordered_semidom} has characteristic zero.*}
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1315
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1316
subclass semiring_char_0
28823
dcbef866c9e2 tuned unfold_locales invocation
haftmann
parents: 28562
diff changeset
  1317
  proof qed (simp add: eq_iff order_eq_iff)
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1318
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1319
text{*Special cases where either operand is zero*}
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1320
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1321
lemma of_nat_0_le_iff [simp]: "0 \<le> of_nat n"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1322
  by (rule of_nat_le_iff [of 0, simplified])
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1323
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1324
lemma of_nat_le_0_iff [simp, noatp]: "of_nat m \<le> 0 \<longleftrightarrow> m = 0"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1325
  by (rule of_nat_le_iff [of _ 0, simplified])
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1326
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1327
lemma of_nat_0_less_iff [simp]: "0 < of_nat n \<longleftrightarrow> 0 < n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1328
  by (rule of_nat_less_iff [of 0, simplified])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1329
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1330
lemma of_nat_less_0_iff [simp]: "\<not> of_nat m < 0"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1331
  by (rule of_nat_less_iff [of _ 0, simplified])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1332
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1333
end
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1334
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1335
context ring_1
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1336
begin
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1337
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1338
lemma of_nat_diff: "n \<le> m \<Longrightarrow> of_nat (m - n) = of_nat m - of_nat n"
29667
53103fc8ffa3 Replaced group_ and ring_simps by algebra_simps;
nipkow
parents: 28952
diff changeset
  1339
by (simp add: algebra_simps of_nat_add [symmetric])
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1340
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1341
end
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1342
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1343
context ordered_idom
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1344
begin
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1345
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1346
lemma abs_of_nat [simp]: "\<bar>of_nat n\<bar> = of_nat n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1347
  unfolding abs_if by auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1348
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1349
end
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1350
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1351
lemma of_nat_id [simp]: "of_nat n = n"
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
  1352
  by (induct n) (auto simp add: One_nat_def)
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1353
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1354
lemma of_nat_eq_id [simp]: "of_nat = id"
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1355
  by (auto simp add: expand_fun_eq)
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1356
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1357
26149
6094349a4de9 tuned heading
haftmann
parents: 26143
diff changeset
  1358
subsection {* The Set of Natural Numbers *}
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1359
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1360
context semiring_1
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1361
begin
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1362
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1363
definition
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1364
  Nats  :: "'a set" where
28562
4e74209f113e `code func` now just `code`
haftmann
parents: 28514
diff changeset
  1365
  [code del]: "Nats = range of_nat"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1366
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1367
notation (xsymbols)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1368
  Nats  ("\<nat>")
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1369
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1370
lemma of_nat_in_Nats [simp]: "of_nat n \<in> \<nat>"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1371
  by (simp add: Nats_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1372
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1373
lemma Nats_0 [simp]: "0 \<in> \<nat>"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1374
apply (simp add: Nats_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1375
apply (rule range_eqI)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1376
apply (rule of_nat_0 [symmetric])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1377
done
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1378
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1379
lemma Nats_1 [simp]: "1 \<in> \<nat>"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1380
apply (simp add: Nats_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1381
apply (rule range_eqI)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1382
apply (rule of_nat_1 [symmetric])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1383
done
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1384
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1385
lemma Nats_add [simp]: "a \<in> \<nat> \<Longrightarrow> b \<in> \<nat> \<Longrightarrow> a + b \<in> \<nat>"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1386
apply (auto simp add: Nats_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1387
apply (rule range_eqI)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1388
apply (rule of_nat_add [symmetric])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1389
done
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1390
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1391
lemma Nats_mult [simp]: "a \<in> \<nat> \<Longrightarrow> b \<in> \<nat> \<Longrightarrow> a * b \<in> \<nat>"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1392
apply (auto simp add: Nats_def)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1393
apply (rule range_eqI)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1394
apply (rule of_nat_mult [symmetric])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1395
done
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1396
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1397
end
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1398
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1399
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1400
subsection {* Further Arithmetic Facts Concerning the Natural Numbers *}
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1401
22845
5f9138bcb3d7 changed code generator invocation syntax
haftmann
parents: 22744
diff changeset
  1402
lemma subst_equals:
5f9138bcb3d7 changed code generator invocation syntax
haftmann
parents: 22744
diff changeset
  1403
  assumes 1: "t = s" and 2: "u = t"
5f9138bcb3d7 changed code generator invocation syntax
haftmann
parents: 22744
diff changeset
  1404
  shows "u = s"
5f9138bcb3d7 changed code generator invocation syntax
haftmann
parents: 22744
diff changeset
  1405
  using 2 1 by (rule trans)
5f9138bcb3d7 changed code generator invocation syntax
haftmann
parents: 22744
diff changeset
  1406
30686
47a32dd1b86e moved generic arith_tac (formerly silent_arith_tac), verbose_arith_tac (formerly arith_tac) to Arith_Data; simple_arith-tac now named linear_arith_tac
haftmann
parents: 30496
diff changeset
  1407
setup Arith_Data.setup
47a32dd1b86e moved generic arith_tac (formerly silent_arith_tac), verbose_arith_tac (formerly arith_tac) to Arith_Data; simple_arith-tac now named linear_arith_tac
haftmann
parents: 30496
diff changeset
  1408
30496
7cdcc9dd95cb vague cleanup in arith proof tools setup: deleted dead code, more proper structures, clearer arrangement
haftmann
parents: 30242
diff changeset
  1409
use "Tools/nat_arith.ML"
7cdcc9dd95cb vague cleanup in arith proof tools setup: deleted dead code, more proper structures, clearer arrangement
haftmann
parents: 30242
diff changeset
  1410
declaration {* K Nat_Arith.setup *}
24091
109f19a13872 added Tools/lin_arith.ML;
wenzelm
parents: 24075
diff changeset
  1411
109f19a13872 added Tools/lin_arith.ML;
wenzelm
parents: 24075
diff changeset
  1412
use "Tools/lin_arith.ML"
31100
6a2e67fe4488 tuned interface of Lin_Arith
haftmann
parents: 31024
diff changeset
  1413
setup {* Lin_Arith.global_setup *}
30686
47a32dd1b86e moved generic arith_tac (formerly silent_arith_tac), verbose_arith_tac (formerly arith_tac) to Arith_Data; simple_arith-tac now named linear_arith_tac
haftmann
parents: 30496
diff changeset
  1414
declaration {* K Lin_Arith.setup *}
24091
109f19a13872 added Tools/lin_arith.ML;
wenzelm
parents: 24075
diff changeset
  1415
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1416
lemmas [arith_split] = nat_diff_split split_min split_max
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1417
27625
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1418
context order
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1419
begin
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1420
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1421
lemma lift_Suc_mono_le:
27627
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1422
  assumes mono: "!!n. f n \<le> f(Suc n)" and "n\<le>n'"
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1423
  shows "f n \<le> f n'"
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1424
proof (cases "n < n'")
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1425
  case True
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1426
  thus ?thesis
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1427
    by (induct n n' rule: less_Suc_induct[consumes 1]) (auto intro: mono)
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1428
qed (insert `n \<le> n'`, auto) -- {*trivial for @{prop "n = n'"} *}
27625
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1429
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1430
lemma lift_Suc_mono_less:
27627
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1431
  assumes mono: "!!n. f n < f(Suc n)" and "n < n'"
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1432
  shows "f n < f n'"
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1433
using `n < n'`
93016de79b02 simplified proofs
krauss
parents: 27625
diff changeset
  1434
by (induct n n' rule: less_Suc_induct[consumes 1]) (auto intro: mono)
27625
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1435
27789
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1436
lemma lift_Suc_mono_less_iff:
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1437
  "(!!n. f n < f(Suc n)) \<Longrightarrow> f(n) < f(m) \<longleftrightarrow> n<m"
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1438
by(blast intro: less_asym' lift_Suc_mono_less[of f]
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1439
         dest: linorder_not_less[THEN iffD1] le_eq_less_or_eq[THEN iffD1])
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1440
27625
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1441
end
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1442
29879
4425849f5db7 Moved FTA into Lib and cleaned it up a little.
nipkow
parents: 29854
diff changeset
  1443
lemma mono_iff_le_Suc: "mono f = (\<forall>n. f n \<le> f (Suc n))"
4425849f5db7 Moved FTA into Lib and cleaned it up a little.
nipkow
parents: 29854
diff changeset
  1444
unfolding mono_def
4425849f5db7 Moved FTA into Lib and cleaned it up a little.
nipkow
parents: 29854
diff changeset
  1445
by (auto intro:lift_Suc_mono_le[of f])
27625
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1446
27789
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1447
lemma mono_nat_linear_lb:
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1448
  "(!!m n::nat. m<n \<Longrightarrow> f m < f n) \<Longrightarrow> f(m)+k \<le> f(m+k)"
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1449
apply(induct_tac k)
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1450
 apply simp
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1451
apply(erule_tac x="m+n" in meta_allE)
30079
293b896b9c25 make proofs work whether or not One_nat_def is a simp rule; replace 1 with Suc 0 in the rhs of some simp rules
huffman
parents: 30056
diff changeset
  1452
apply(erule_tac x="Suc(m+n)" in meta_allE)
27789
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1453
apply simp
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1454
done
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1455
1bf827e3258d added lemmas
nipkow
parents: 27679
diff changeset
  1456
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1457
text{*Subtraction laws, mostly by Clemens Ballarin*}
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1458
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1459
lemma diff_less_mono: "[| a < (b::nat); c \<le> a |] ==> a-c < b-c"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1460
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1461
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1462
lemma less_diff_conv: "(i < j-k) = (i+k < (j::nat))"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1463
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1464
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1465
lemma le_diff_conv: "(j-k \<le> (i::nat)) = (j \<le> i+k)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1466
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1467
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1468
lemma le_diff_conv2: "k \<le> j ==> (i \<le> j-k) = (i+k \<le> (j::nat))"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1469
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1470
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1471
lemma diff_diff_cancel [simp]: "i \<le> (n::nat) ==> n - (n - i) = i"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1472
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1473
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1474
lemma le_add_diff: "k \<le> (n::nat) ==> m \<le> n + m - k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1475
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1476
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1477
(*Replaces the previous diff_less and le_diff_less, which had the stronger
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1478
  second premise n\<le>m*)
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1479
lemma diff_less[simp]: "!!m::nat. [| 0<n; 0<m |] ==> m - n < m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1480
by arith
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1481
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1482
text {* Simplification of relational expressions involving subtraction *}
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1483
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1484
lemma diff_diff_eq: "[| k \<le> m;  k \<le> (n::nat) |] ==> ((m-k) - (n-k)) = (m-n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1485
by (simp split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1486
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1487
lemma eq_diff_iff: "[| k \<le> m;  k \<le> (n::nat) |] ==> (m-k = n-k) = (m=n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1488
by (auto split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1489
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1490
lemma less_diff_iff: "[| k \<le> m;  k \<le> (n::nat) |] ==> (m-k < n-k) = (m<n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1491
by (auto split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1492
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1493
lemma le_diff_iff: "[| k \<le> m;  k \<le> (n::nat) |] ==> (m-k \<le> n-k) = (m\<le>n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1494
by (auto split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1495
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1496
text{*(Anti)Monotonicity of subtraction -- by Stephan Merz*}
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1497
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1498
(* Monotonicity of subtraction in first argument *)
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1499
lemma diff_le_mono: "m \<le> (n::nat) ==> (m-l) \<le> (n-l)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1500
by (simp split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1501
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1502
lemma diff_le_mono2: "m \<le> (n::nat) ==> (l-n) \<le> (l-m)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1503
by (simp split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1504
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1505
lemma diff_less_mono2: "[| m < (n::nat); m<l |] ==> (l-n) < (l-m)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1506
by (simp split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1507
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1508
lemma diffs0_imp_equal: "!!m::nat. [| m-n = 0; n-m = 0 |] ==>  m=n"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1509
by (simp split add: nat_diff_split)
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1510
26143
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1511
lemma min_diff: "min (m - (i::nat)) (n - i) = min m n - i"
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1512
unfolding min_def by auto
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1513
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1514
lemma inj_on_diff_nat: 
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1515
  assumes k_le_n: "\<forall>n \<in> N. k \<le> (n::nat)"
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1516
  shows "inj_on (\<lambda>n. n - k) N"
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1517
proof (rule inj_onI)
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1518
  fix x y
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1519
  assume a: "x \<in> N" "y \<in> N" "x - k = y - k"
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1520
  with k_le_n have "x - k + k = y - k + k" by auto
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1521
  with a k_le_n show "x = y" by auto
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1522
qed
314c0bcb7df7 Added useful general lemmas from the work with the HeapMonad
bulwahn
parents: 26101
diff changeset
  1523
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1524
text{*Rewriting to pull differences out*}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1525
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1526
lemma diff_diff_right [simp]: "k\<le>j --> i - (j - k) = i + (k::nat) - j"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1527
by arith
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1528
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1529
lemma diff_Suc_diff_eq1 [simp]: "k \<le> j ==> m - Suc (j - k) = m + k - Suc j"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1530
by arith
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1531
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1532
lemma diff_Suc_diff_eq2 [simp]: "k \<le> j ==> Suc (j - k) - m = Suc j - (k + m)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1533
by arith
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1534
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1535
text{*Lemmas for ex/Factorization*}
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1536
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1537
lemma one_less_mult: "[| Suc 0 < n; Suc 0 < m |] ==> Suc 0 < m*n"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1538
by (cases m) auto
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1539
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1540
lemma n_less_m_mult_n: "[| Suc 0 < n; Suc 0 < m |] ==> n<m*n"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1541
by (cases m) auto
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1542
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1543
lemma n_less_n_mult_m: "[| Suc 0 < n; Suc 0 < m |] ==> n<n*m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1544
by (cases m) auto
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1545
23001
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1546
text {* Specialized induction principles that work "backwards": *}
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1547
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1548
lemma inc_induct[consumes 1, case_names base step]:
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1549
  assumes less: "i <= j"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1550
  assumes base: "P j"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1551
  assumes step: "!!i. [| i < j; P (Suc i) |] ==> P i"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1552
  shows "P i"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1553
  using less
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1554
proof (induct d=="j - i" arbitrary: i)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1555
  case (0 i)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1556
  hence "i = j" by simp
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1557
  with base show ?case by simp
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1558
next
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1559
  case (Suc d i)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1560
  hence "i < j" "P (Suc i)"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1561
    by simp_all
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1562
  thus "P i" by (rule step)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1563
qed
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1564
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1565
lemma strict_inc_induct[consumes 1, case_names base step]:
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1566
  assumes less: "i < j"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1567
  assumes base: "!!i. j = Suc i ==> P i"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1568
  assumes step: "!!i. [| i < j; P (Suc i) |] ==> P i"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1569
  shows "P i"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1570
  using less
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1571
proof (induct d=="j - i - 1" arbitrary: i)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1572
  case (0 i)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1573
  with `i < j` have "j = Suc i" by simp
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1574
  with base show ?case by simp
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1575
next
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1576
  case (Suc d i)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1577
  hence "i < j" "P (Suc i)"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1578
    by simp_all
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1579
  thus "P i" by (rule step)
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1580
qed
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1581
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1582
lemma zero_induct_lemma: "P k ==> (!!n. P (Suc n) ==> P n) ==> P (k - i)"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1583
  using inc_induct[of "k - i" k P, simplified] by blast
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1584
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1585
lemma zero_induct: "P k ==> (!!n. P (Suc n) ==> P n) ==> P 0"
3608f0362a91 added induction principles for induction "backwards": P (Suc n) ==> P n
krauss
parents: 22920
diff changeset
  1586
  using inc_induct[of 0 k P] by blast
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1587
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1588
lemma nat_not_singleton: "(\<forall>x. x = (0::nat)) = False"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1589
  by auto
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1590
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1591
(*The others are
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1592
      i - j - k = i - (j + k),
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1593
      k \<le> j ==> j - k + i = j + i - k,
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1594
      k \<le> j ==> i + (j - k) = i + j - k *)
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1595
lemmas add_diff_assoc = diff_add_assoc [symmetric]
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1596
lemmas add_diff_assoc2 = diff_add_assoc2[symmetric]
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1597
declare diff_diff_left [simp]  add_diff_assoc [simp] add_diff_assoc2[simp]
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1598
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1599
text{*At present we prove no analogue of @{text not_less_Least} or @{text
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1600
Least_Suc}, since there appears to be no need.*}
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
  1601
27625
3a45b555001a added lemmas
nipkow
parents: 27213
diff changeset
  1602
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1603
subsection {* size of a datatype value *}
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1604
29608
564ea783ace8 no base sort in class import
haftmann
parents: 28952
diff changeset
  1605
class size =
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
  1606
  fixes size :: "'a \<Rightarrow> nat" -- {* see further theory @{text Wellfounded} *}
23852
3736cdf9398b moved set Nats to Nat.thy
haftmann
parents: 23740
diff changeset
  1607
25193
e2e1a4b00de3 various localizations
haftmann
parents: 25162
diff changeset
  1608
end