src/HOL/Nat.thy
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(*  Title:      HOL/Nat.thy
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    Author:     Tobias Nipkow and Lawrence C Paulson and Markus Wenzel
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Type "nat" is a linear order, and a datatype; arithmetic operators + -
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and * (for div and mod, see theory Divides).
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*)
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header {* Natural numbers *}
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theory Nat
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imports Inductive Typedef Fun Fields
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begin
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ML_file "~~/src/Tools/rat.ML"
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ML_file "Tools/arith_data.ML"
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ML_file "~~/src/Provers/Arith/fast_lin_arith.ML"
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subsection {* Type @{text ind} *}
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typedecl ind
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axiomatization Zero_Rep :: ind and Suc_Rep :: "ind => ind" where
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  -- {* the axiom of infinity in 2 parts *}
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  Suc_Rep_inject:       "Suc_Rep x = Suc_Rep y ==> x = y" and
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  Suc_Rep_not_Zero_Rep: "Suc_Rep x \<noteq> Zero_Rep"
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subsection {* Type nat *}
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text {* Type definition *}
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inductive Nat :: "ind \<Rightarrow> bool" where
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  Zero_RepI: "Nat Zero_Rep"
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| Suc_RepI: "Nat i \<Longrightarrow> Nat (Suc_Rep i)"
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typedef nat = "{n. Nat n}"
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  morphisms Rep_Nat Abs_Nat
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  using Nat.Zero_RepI by auto
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lemma Nat_Rep_Nat:
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  "Nat (Rep_Nat n)"
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  using Rep_Nat by simp
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lemma Nat_Abs_Nat_inverse:
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  "Nat n \<Longrightarrow> Rep_Nat (Abs_Nat n) = n"
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  using Abs_Nat_inverse by simp
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lemma Nat_Abs_Nat_inject:
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  "Nat n \<Longrightarrow> Nat m \<Longrightarrow> Abs_Nat n = Abs_Nat m \<longleftrightarrow> n = m"
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  using Abs_Nat_inject by simp
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instantiation nat :: zero
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begin
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definition Zero_nat_def:
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  "0 = Abs_Nat Zero_Rep"
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instance ..
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end
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definition Suc :: "nat \<Rightarrow> nat" where
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  "Suc n = Abs_Nat (Suc_Rep (Rep_Nat n))"
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lemma Suc_not_Zero: "Suc m \<noteq> 0"
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  by (simp add: Zero_nat_def Suc_def Suc_RepI Zero_RepI Nat_Abs_Nat_inject Suc_Rep_not_Zero_Rep Nat_Rep_Nat)
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lemma Zero_not_Suc: "0 \<noteq> Suc m"
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  by (rule not_sym, rule Suc_not_Zero not_sym)
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lemma Suc_Rep_inject': "Suc_Rep x = Suc_Rep y \<longleftrightarrow> x = y"
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  by (rule iffI, rule Suc_Rep_inject) simp_all
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rep_datatype "0 \<Colon> nat" Suc
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  apply (unfold Zero_nat_def Suc_def)
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  apply (rule Rep_Nat_inverse [THEN subst]) -- {* types force good instantiation *}
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   apply (erule Nat_Rep_Nat [THEN Nat.induct])
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   apply (iprover elim: Nat_Abs_Nat_inverse [THEN subst])
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    apply (simp_all add: Nat_Abs_Nat_inject Nat_Rep_Nat
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      Suc_RepI Zero_RepI Suc_Rep_not_Zero_Rep
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      Suc_Rep_not_Zero_Rep [symmetric]
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      Suc_Rep_inject' Rep_Nat_inject)
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  done
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lemma nat_induct [case_names 0 Suc, induct type: nat]:
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  -- {* for backward compatibility -- names of variables differ *}
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  fixes n
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  assumes "P 0"
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    and "\<And>n. P n \<Longrightarrow> P (Suc n)"
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  shows "P n"
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  using assms by (rule nat.induct)
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declare nat.exhaust [case_names 0 Suc, cases type: nat]
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lemmas nat_rec_0 = nat.recs(1)
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  and nat_rec_Suc = nat.recs(2)
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lemmas nat_case_0 = nat.cases(1)
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  and nat_case_Suc = nat.cases(2)
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text {* Injectiveness and distinctness lemmas *}
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lemma inj_Suc[simp]: "inj_on Suc N"
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  by (simp add: inj_on_def)
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lemma Suc_neq_Zero: "Suc m = 0 \<Longrightarrow> R"
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by (rule notE, rule Suc_not_Zero)
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lemma Zero_neq_Suc: "0 = Suc m \<Longrightarrow> R"
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by (rule Suc_neq_Zero, erule sym)
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lemma Suc_inject: "Suc x = Suc y \<Longrightarrow> x = y"
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by (rule inj_Suc [THEN injD])
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lemma n_not_Suc_n: "n \<noteq> Suc n"
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by (induct n) simp_all
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lemma Suc_n_not_n: "Suc n \<noteq> n"
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by (rule not_sym, rule n_not_Suc_n)
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text {* A special form of induction for reasoning
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  about @{term "m < n"} and @{term "m - n"} *}
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lemma diff_induct: "(!!x. P x 0) ==> (!!y. P 0 (Suc y)) ==>
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    (!!x y. P x y ==> P (Suc x) (Suc y)) ==> P m n"
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  apply (rule_tac x = m in spec)
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  apply (induct n)
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  prefer 2
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  apply (rule allI)
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  apply (induct_tac x, iprover+)
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  done
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subsection {* Arithmetic operators *}
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instantiation nat :: comm_monoid_diff
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begin
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primrec plus_nat where
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  add_0:      "0 + n = (n\<Colon>nat)"
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| add_Suc:  "Suc m + n = Suc (m + n)"
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lemma add_0_right [simp]: "m + 0 = (m::nat)"
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  by (induct m) simp_all
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lemma add_Suc_right [simp]: "m + Suc n = Suc (m + n)"
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  by (induct m) simp_all
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declare add_0 [code]
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lemma add_Suc_shift [code]: "Suc m + n = m + Suc n"
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  by simp
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primrec minus_nat where
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  diff_0 [code]: "m - 0 = (m\<Colon>nat)"
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| diff_Suc: "m - Suc n = (case m - n of 0 => 0 | Suc k => k)"
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declare diff_Suc [simp del]
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lemma diff_0_eq_0 [simp, code]: "0 - n = (0::nat)"
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  by (induct n) (simp_all add: diff_Suc)
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lemma diff_Suc_Suc [simp, code]: "Suc m - Suc n = m - n"
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  by (induct n) (simp_all add: diff_Suc)
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instance proof
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  fix n m q :: nat
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  show "(n + m) + q = n + (m + q)" by (induct n) simp_all
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  show "n + m = m + n" by (induct n) simp_all
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  show "0 + n = n" by simp
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  show "n - 0 = n" by simp
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  show "0 - n = 0" by simp
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  show "(q + n) - (q + m) = n - m" by (induct q) simp_all
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  show "n - m - q = n - (m + q)" by (induct q) (simp_all add: diff_Suc)
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qed
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end
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hide_fact (open) add_0 add_0_right diff_0
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instantiation nat :: comm_semiring_1_cancel
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begin
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definition
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  One_nat_def [simp]: "1 = Suc 0"
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primrec times_nat where
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  mult_0:     "0 * n = (0\<Colon>nat)"
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| mult_Suc: "Suc m * n = n + (m * n)"
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lemma mult_0_right [simp]: "(m::nat) * 0 = 0"
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  by (induct m) simp_all
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lemma mult_Suc_right [simp]: "m * Suc n = m + (m * n)"
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  by (induct m) (simp_all add: add_left_commute)
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lemma add_mult_distrib: "(m + n) * k = (m * k) + ((n * k)::nat)"
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  by (induct m) (simp_all add: add_assoc)
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instance proof
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  fix n m q :: nat
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  show "0 \<noteq> (1::nat)" unfolding One_nat_def by simp
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  show "1 * n = n" unfolding One_nat_def by simp
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  show "n * m = m * n" by (induct n) simp_all
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  show "(n * m) * q = n * (m * q)" by (induct n) (simp_all add: add_mult_distrib)
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  show "(n + m) * q = n * q + m * q" by (rule add_mult_distrib)
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  assume "n + m = n + q" thus "m = q" by (induct n) simp_all
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qed
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end
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subsubsection {* Addition *}
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lemma nat_add_assoc: "(m + n) + k = m + ((n + k)::nat)"
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  by (rule add_assoc)
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lemma nat_add_commute: "m + n = n + (m::nat)"
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  by (rule add_commute)
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lemma nat_add_left_commute: "x + (y + z) = y + ((x + z)::nat)"
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  by (rule add_left_commute)
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lemma nat_add_left_cancel [simp]: "(k + m = k + n) = (m = (n::nat))"
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  by (rule add_left_cancel)
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lemma nat_add_right_cancel [simp]: "(m + k = n + k) = (m=(n::nat))"
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  by (rule add_right_cancel)
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text {* Reasoning about @{text "m + 0 = 0"}, etc. *}
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lemma add_is_0 [iff]:
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  fixes m n :: nat
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  shows "(m + n = 0) = (m = 0 & n = 0)"
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  by (cases m) simp_all
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lemma add_is_1:
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  "(m+n= Suc 0) = (m= Suc 0 & n=0 | m=0 & n= Suc 0)"
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  by (cases m) simp_all
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lemma one_is_add:
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  "(Suc 0 = m + n) = (m = Suc 0 & n = 0 | m = 0 & n = Suc 0)"
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  by (rule trans, rule eq_commute, rule add_is_1)
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lemma add_eq_self_zero:
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  fixes m n :: nat
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  shows "m + n = m \<Longrightarrow> n = 0"
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  by (induct m) simp_all
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lemma inj_on_add_nat[simp]: "inj_on (%n::nat. n+k) N"
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  apply (induct k)
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   apply simp
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  apply(drule comp_inj_on[OF _ inj_Suc])
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  apply (simp add:o_def)
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  done
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lemma Suc_eq_plus1: "Suc n = n + 1"
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  unfolding One_nat_def by simp
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9a91b163bb71 move lemmas from Nat_Numeral.thy to Nat.thy
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lemma Suc_eq_plus1_left: "Suc n = 1 + n"
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  unfolding One_nat_def by simp
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subsubsection {* Difference *}
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lemma diff_self_eq_0 [simp]: "(m\<Colon>nat) - m = 0"
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  by (induct m) simp_all
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lemma diff_diff_left: "(i::nat) - j - k = i - (j + k)"
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  by (induct i j rule: diff_induct) simp_all
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lemma Suc_diff_diff [simp]: "(Suc m - n) - Suc k = m - n - k"
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  by (simp add: diff_diff_left)
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lemma diff_commute: "(i::nat) - j - k = i - k - j"
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  by (simp add: diff_diff_left add_commute)
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lemma diff_add_inverse: "(n + m) - n = (m::nat)"
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  by (induct n) simp_all
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lemma diff_add_inverse2: "(m + n) - n = (m::nat)"
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  by (simp add: diff_add_inverse add_commute [of m n])
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lemma diff_cancel: "(k + m) - (k + n) = m - (n::nat)"
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  by (induct k) simp_all
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lemma diff_cancel2: "(m + k) - (n + k) = m - (n::nat)"
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  by (simp add: diff_cancel add_commute)
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lemma diff_add_0: "n - (n + m) = (0::nat)"
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  by (induct n) simp_all
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ecb557b021b2 add lemma diff_Suc_1
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lemma diff_Suc_1 [simp]: "Suc n - 1 = n"
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  unfolding One_nat_def by simp
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text {* Difference distributes over multiplication *}
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lemma diff_mult_distrib: "((m::nat) - n) * k = (m * k) - (n * k)"
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by (induct m n rule: diff_induct) (simp_all add: diff_cancel)
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diff changeset
   301
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
   302
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
   303
  -- {* 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
   304
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   305
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   306
subsubsection {* Multiplication *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   307
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   308
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
   309
  by (rule mult_assoc)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   310
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   311
lemma nat_mult_commute: "m * n = n * (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   312
  by (rule mult_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   313
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   314
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
   315
  by (rule right_distrib)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   316
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   317
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
   318
  by (induct m) auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   319
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   320
lemmas nat_distrib =
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   321
  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
   322
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
   323
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
   324
  apply (induct m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   325
   apply simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   326
  apply (induct n)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   327
   apply auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   328
  done
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   329
35828
46cfc4b8112e now use "Named_Thms" for "noatp", and renamed "noatp" to "no_atp"
blanchet
parents: 35633
diff changeset
   330
lemma one_eq_mult_iff [simp,no_atp]: "(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
   331
  apply (rule trans)
44890
22f665a2e91c new fastforce replacing fastsimp - less confusing name
nipkow
parents: 44848
diff changeset
   332
  apply (rule_tac [2] mult_eq_1_iff, fastforce)
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   333
  done
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   334
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
   335
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
   336
  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
   337
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
   338
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
   339
  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
   340
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   341
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
   342
proof -
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   343
  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
   344
  proof (induct n arbitrary: m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   345
    case 0 then show "m = 0" by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   346
  next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   347
    case (Suc n) then show "m = Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   348
      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
   349
  qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   350
  then show ?thesis by auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   351
qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   352
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   353
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
   354
  by (simp add: mult_commute)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   355
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   356
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
   357
  by (subst mult_cancel1) simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   358
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   359
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   360
subsection {* Orders on @{typ nat} *}
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   361
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   362
subsubsection {* Operation definition *}
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   363
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   364
instantiation nat :: linorder
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   365
begin
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   366
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   367
primrec less_eq_nat where
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   368
  "(0\<Colon>nat) \<le> n \<longleftrightarrow> True"
44325
84696670feb1 more uniform formatting of specifications
haftmann
parents: 44278
diff changeset
   369
| "Suc m \<le> n \<longleftrightarrow> (case n of 0 \<Rightarrow> False | Suc n \<Rightarrow> m \<le> n)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   370
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   371
declare less_eq_nat.simps [simp del]
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   372
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
   373
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
   374
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   375
definition less_nat where
28514
da83a614c454 tuned of_nat code generation
haftmann
parents: 27823
diff changeset
   376
  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
   377
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   378
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
   379
  by (simp add: less_eq_nat.simps(2))
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   380
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   381
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
   382
  unfolding less_eq_Suc_le ..
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   383
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   384
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
   385
  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
   386
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   387
lemma not_less0 [iff]: "\<not> n < (0\<Colon>nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   388
  by (simp add: less_eq_Suc_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   389
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   390
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
   391
  by simp
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_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
   394
  by (simp add: less_eq_Suc_le)
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_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
   397
  by (simp add: less_eq_Suc_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   398
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   399
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
   400
  by (induct m arbitrary: n)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   401
    (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
   402
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   403
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
   404
  by (cases n) (auto intro: le_SucI)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   405
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   406
lemma less_SucI: "m < n \<Longrightarrow> m < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   407
  by (simp add: less_eq_Suc_le) (erule Suc_leD)
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   408
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   409
lemma Suc_lessD: "Suc m < n \<Longrightarrow> m < n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   410
  by (simp add: less_eq_Suc_le) (erule Suc_leD)
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   411
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
   412
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
   413
proof
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   414
  fix n m :: nat
27679
haftmann
parents: 27627
diff changeset
   415
  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
   416
  proof (induct n arbitrary: m)
27679
haftmann
parents: 27627
diff changeset
   417
    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
   418
  next
27679
haftmann
parents: 27627
diff changeset
   419
    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
   420
  qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   421
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   422
  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
   423
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   424
  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
   425
  then show "n = m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   426
    by (induct n arbitrary: m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   427
      (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
   428
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   429
  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
   430
  then show "n \<le> q"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   431
  proof (induct n arbitrary: m q)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   432
    case 0 show ?case by simp
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   433
  next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   434
    case (Suc n) then show ?case
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   435
      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
   436
        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
   437
        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
   438
  qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   439
next
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   440
  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
   441
    by (induct n arbitrary: m)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   442
      (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
   443
qed
25510
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   444
38c15efe603b adjustions to due to instance target
haftmann
parents: 25502
diff changeset
   445
end
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   446
29652
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   447
instantiation nat :: bot
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   448
begin
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   449
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   450
definition bot_nat :: nat where
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   451
  "bot_nat = 0"
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   452
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   453
instance proof
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   454
qed (simp add: bot_nat_def)
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   455
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   456
end
f4c6e546b7fe nat is a bot instance
haftmann
parents: 29608
diff changeset
   457
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   458
subsubsection {* Introduction properties *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   459
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   460
lemma lessI [iff]: "n < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   461
  by (simp add: less_Suc_eq_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   462
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   463
lemma zero_less_Suc [iff]: "0 < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   464
  by (simp add: less_Suc_eq_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   465
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   466
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   467
subsubsection {* Elimination properties *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   468
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   469
lemma less_not_refl: "~ n < (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   470
  by (rule order_less_irrefl)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   471
26335
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   472
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
   473
  by (rule not_sym) (rule less_imp_neq) 
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   474
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   475
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
   476
  by (rule less_imp_neq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   477
26335
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   478
lemma less_irrefl_nat: "(n::nat) < n ==> R"
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
   479
  by (rule notE, rule less_not_refl)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   480
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   481
lemma less_zeroE: "(n::nat) < 0 ==> R"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   482
  by (rule notE) (rule not_less0)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   483
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   484
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
   485
  unfolding less_Suc_eq_le le_less ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   486
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
   487
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
   488
  by (simp add: less_Suc_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   489
35828
46cfc4b8112e now use "Named_Thms" for "noatp", and renamed "noatp" to "no_atp"
blanchet
parents: 35633
diff changeset
   490
lemma less_one [iff, no_atp]: "(n < (1::nat)) = (n = 0)"
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
   491
  unfolding One_nat_def by (rule less_Suc0)
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 Suc_mono: "m < n ==> Suc m < Suc n"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   494
  by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   495
14302
6c24235e8d5d *** empty log message ***
nipkow
parents: 14267
diff changeset
   496
text {* "Less than" is antisymmetric, sort of *}
6c24235e8d5d *** empty log message ***
nipkow
parents: 14267
diff changeset
   497
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
   498
  unfolding not_less less_Suc_eq_le by (rule antisym)
14302
6c24235e8d5d *** empty log message ***
nipkow
parents: 14267
diff changeset
   499
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   500
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
   501
  by (rule linorder_neq_iff)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   502
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   503
lemma nat_less_cases: assumes major: "(m::nat) < n ==> P n m"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   504
  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
   505
  shows "P n m"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   506
  apply (rule less_linear [THEN disjE])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   507
  apply (erule_tac [2] disjE)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   508
  apply (erule lessCase)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   509
  apply (erule sym [THEN eqCase])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   510
  apply (erule major)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   511
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   512
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   513
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   514
subsubsection {* Inductive (?) properties *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   515
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   516
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
   517
  unfolding less_eq_Suc_le [of m] le_less by simp 
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   518
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   519
lemma lessE:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   520
  assumes major: "i < k"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   521
  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
   522
  shows P
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   523
proof -
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   524
  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
   525
    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
   526
  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
   527
    by (clarsimp simp add: less_le)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   528
  with p1 p2 show P by auto
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   529
qed
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   530
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   531
lemma less_SucE: assumes major: "m < Suc n"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   532
  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
   533
  apply (rule major [THEN lessE])
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   534
  apply (rule eq, blast)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   535
  apply (rule less, blast)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   536
  done
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 Suc_lessE: assumes major: "Suc i < k"
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   539
  and minor: "!!j. i < j ==> k = Suc j ==> P" shows P
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   540
  apply (rule major [THEN lessE])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   541
  apply (erule lessI [THEN minor])
14208
144f45277d5a misc tidying
paulson
parents: 14193
diff changeset
   542
  apply (erule Suc_lessD [THEN minor], assumption)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   543
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   544
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   545
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
   546
  by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   547
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   548
lemma less_trans_Suc:
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   549
  assumes le: "i < j" shows "j < k ==> Suc i < k"
14208
144f45277d5a misc tidying
paulson
parents: 14193
diff changeset
   550
  apply (induct k, simp_all)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   551
  apply (insert le)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   552
  apply (simp add: less_Suc_eq)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   553
  apply (blast dest: Suc_lessD)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   554
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   555
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   556
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
   557
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
   558
  unfolding not_less less_Suc_eq_le ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   559
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   560
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
   561
  unfolding not_le Suc_le_eq ..
21243
afffe1f72143 removed theory NatArith (now part of Nat);
wenzelm
parents: 21191
diff changeset
   562
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
   563
text {* Properties of "less than or equal" *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   564
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   565
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
   566
  unfolding less_Suc_eq_le .
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   567
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   568
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
   569
  unfolding not_le less_Suc_eq_le ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   570
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   571
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
   572
  by (simp add: less_Suc_eq_le [symmetric] less_Suc_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   573
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   574
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
   575
  by (drule le_Suc_eq [THEN iffD1], iprover+)
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
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
   578
  unfolding 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
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
   581
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
   582
  unfolding Suc_le_eq .
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   583
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
   584
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
   585
  unfolding less_eq_Suc_le by (rule Suc_leD)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   586
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   587
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
   588
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
   589
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   590
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   591
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
   592
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   593
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
   594
  unfolding le_less .
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_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
   597
  by (rule le_less)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   598
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   599
text {* Useful with @{text blast}. *}
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   600
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
   601
  by auto
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   602
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   603
lemma le_refl: "n \<le> (n::nat)"
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   604
  by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   605
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   606
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
   607
  by (rule order_trans)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   608
33657
a4179bf442d1 renamed lemmas "anti_sym" -> "antisym"
nipkow
parents: 33364
diff changeset
   609
lemma le_antisym: "[| 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
   610
  by (rule antisym)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   611
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   612
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
   613
  by (rule less_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   614
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   615
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
   616
  unfolding less_le ..
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   617
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   618
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
   619
  by (rule linear)
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   620
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   621
lemmas linorder_neqE_nat = linorder_neqE [where 'a = nat]
15921
b6e345548913 Fixing a problem with lin.arith.
nipkow
parents: 15539
diff changeset
   622
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   623
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
   624
  unfolding less_Suc_eq_le by auto
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   625
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   626
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
   627
  unfolding not_less by (rule le_less_Suc_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   628
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   629
lemmas not_less_simps = not_less_less_Suc_eq le_less_Suc_eq
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   630
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   631
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
   632
NOTE USE OF @{text "=="} *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   633
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
   634
by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   635
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   636
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
   637
by simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   638
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   639
lemma not0_implies_Suc: "n \<noteq> 0 ==> \<exists>m. n = Suc m"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   640
by (cases n) simp_all
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   641
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   642
lemma gr0_implies_Suc: "n > 0 ==> \<exists>m. n = Suc m"
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   643
by (cases n) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   644
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   645
lemma gr_implies_not0: fixes n :: nat shows "m<n ==> n \<noteq> 0"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   646
by (cases n) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   647
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   648
lemma neq0_conv[iff]: fixes n :: nat shows "(n \<noteq> 0) = (0 < n)"
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   649
by (cases n) simp_all
25140
273772abbea2 More changes from >0 to ~=0::nat
nipkow
parents: 25134
diff changeset
   650
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   651
text {* This theorem is useful with @{text blast} *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   652
lemma gr0I: "((n::nat) = 0 ==> False) ==> 0 < n"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   653
by (rule neq0_conv[THEN iffD1], iprover)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   654
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   655
lemma gr0_conv_Suc: "(0 < n) = (\<exists>m. n = Suc m)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   656
by (fast intro: not0_implies_Suc)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   657
35828
46cfc4b8112e now use "Named_Thms" for "noatp", and renamed "noatp" to "no_atp"
blanchet
parents: 35633
diff changeset
   658
lemma not_gr0 [iff,no_atp]: "!!n::nat. (~ (0 < n)) = (n = 0)"
25134
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   659
using neq0_conv by blast
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   660
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   661
lemma Suc_le_D: "(Suc n \<le> m') ==> (? m. m' = Suc m)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   662
by (induct m') simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   663
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   664
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
   665
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
   666
by (cases m) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   667
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   668
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   669
subsubsection {* Monotonicity of Addition *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   670
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
   671
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
   672
by (simp add: diff_Suc split: nat.split)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   673
30128
365ee7319b86 revert some Suc 0 lemmas back to their original forms; added some simp rules for (1::nat)
huffman
parents: 30093
diff changeset
   674
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
   675
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
   676
14331
8dbbb7cf3637 re-organized numeric lemmas
paulson
parents: 14302
diff changeset
   677
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
   678
by (induct k) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   679
14331
8dbbb7cf3637 re-organized numeric lemmas
paulson
parents: 14302
diff changeset
   680
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
   681
by (induct k) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   682
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   683
lemma add_gr_0 [iff]: "!!m::nat. (m + n > 0) = (m>0 | n>0)"
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   684
by(auto dest:gr0_implies_Suc)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   685
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   686
text {* strict, in 1st argument *}
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   687
lemma add_less_mono1: "i < j ==> i + k < j + (k::nat)"
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
   688
by (induct k) simp_all
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   689
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   690
text {* strict, in both arguments *}
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   691
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
   692
  apply (rule add_less_mono1 [THEN less_trans], assumption+)
15251
bb6f072c8d10 converted some induct_tac to induct
paulson
parents: 15140
diff changeset
   693
  apply (induct j, simp_all)
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   694
  done
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   695
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   696
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
   697
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
   698
  apply (induct n)
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   699
  apply (simp_all add: order_le_less)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   700
  apply (blast elim!: less_SucE
35047
1b2bae06c796 hide fact Nat.add_0_right; make add_0_right from Groups priority
haftmann
parents: 35028
diff changeset
   701
               intro!: Nat.add_0_right [symmetric] add_Suc_right [symmetric])
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   702
  done
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   703
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   704
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
   705
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
   706
apply(auto simp: gr0_conv_Suc)
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   707
apply (induct_tac m)
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   708
apply (simp_all add: add_less_mono)
3d4953e88449 Eliminated most of the neq0_conv occurrences. As a result, many
nipkow
parents: 25111
diff changeset
   709
done
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   710
14740
c8e1937110c2 fixed latex problems
nipkow
parents: 14738
diff changeset
   711
text{*The naturals form an ordered @{text comm_semiring_1_cancel}*}
35028
108662d50512 more consistent naming of type classes involving orderings (and lattices) -- c.f. NEWS
haftmann
parents: 34208
diff changeset
   712
instance nat :: linordered_semidom
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   713
proof
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
   714
  fix i j k :: nat
14348
744c868ee0b7 Defining the type class "ringpower" and deleting superseded theorems for
paulson
parents: 14341
diff changeset
   715
  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
   716
  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
   717
  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
   718
qed
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   719
30056
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   720
instance nat :: no_zero_divisors
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   721
proof
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   722
  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
   723
qed
0a35bee25c20 added lemmas
nipkow
parents: 29879
diff changeset
   724
44817
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   725
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   726
subsubsection {* @{term min} and @{term max} *}
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   727
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   728
lemma mono_Suc: "mono Suc"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   729
by (rule monoI) simp
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   730
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   731
lemma min_0L [simp]: "min 0 n = (0::nat)"
45931
99cf6e470816 weaken preconditions on lemmas
noschinl
parents: 45833
diff changeset
   732
by (rule min_absorb1) simp
44817
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   733
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   734
lemma min_0R [simp]: "min n 0 = (0::nat)"
45931
99cf6e470816 weaken preconditions on lemmas
noschinl
parents: 45833
diff changeset
   735
by (rule min_absorb2) simp
44817
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   736
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   737
lemma min_Suc_Suc [simp]: "min (Suc m) (Suc n) = Suc (min m n)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   738
by (simp add: mono_Suc min_of_mono)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   739
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   740
lemma min_Suc1:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   741
   "min (Suc n) m = (case m of 0 => 0 | Suc m' => Suc(min n m'))"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   742
by (simp split: nat.split)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   743
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   744
lemma min_Suc2:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   745
   "min m (Suc n) = (case m of 0 => 0 | Suc m' => Suc(min m' n))"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   746
by (simp split: nat.split)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   747
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   748
lemma max_0L [simp]: "max 0 n = (n::nat)"
45931
99cf6e470816 weaken preconditions on lemmas
noschinl
parents: 45833
diff changeset
   749
by (rule max_absorb2) simp
44817
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   750
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   751
lemma max_0R [simp]: "max n 0 = (n::nat)"
45931
99cf6e470816 weaken preconditions on lemmas
noschinl
parents: 45833
diff changeset
   752
by (rule max_absorb1) simp
44817
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   753
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   754
lemma max_Suc_Suc [simp]: "max (Suc m) (Suc n) = Suc(max m n)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   755
by (simp add: mono_Suc max_of_mono)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   756
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   757
lemma max_Suc1:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   758
   "max (Suc n) m = (case m of 0 => Suc n | Suc m' => Suc(max n m'))"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   759
by (simp split: nat.split)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   760
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   761
lemma max_Suc2:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   762
   "max m (Suc n) = (case m of 0 => Suc n | Suc m' => Suc(max m' n))"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   763
by (simp split: nat.split)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   764
44817
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   765
lemma nat_mult_min_left:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   766
  fixes m n q :: nat
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   767
  shows "min m n * q = min (m * q) (n * q)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   768
  by (simp add: min_def not_le) (auto dest: mult_right_le_imp_le mult_right_less_imp_less le_less_trans)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   769
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   770
lemma nat_mult_min_right:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   771
  fixes m n q :: nat
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   772
  shows "m * min n q = min (m * n) (m * q)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   773
  by (simp add: min_def not_le) (auto dest: mult_left_le_imp_le mult_left_less_imp_less le_less_trans)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   774
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   775
lemma nat_add_max_left:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   776
  fixes m n q :: nat
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   777
  shows "max m n + q = max (m + q) (n + q)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   778
  by (simp add: max_def)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   779
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   780
lemma nat_add_max_right:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   781
  fixes m n q :: nat
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   782
  shows "m + max n q = max (m + n) (m + q)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   783
  by (simp add: max_def)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   784
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   785
lemma nat_mult_max_left:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   786
  fixes m n q :: nat
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   787
  shows "max m n * q = max (m * q) (n * q)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   788
  by (simp add: max_def not_le) (auto dest: mult_right_le_imp_le mult_right_less_imp_less le_less_trans)
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   789
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   790
lemma nat_mult_max_right:
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   791
  fixes m n q :: nat
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   792
  shows "m * max n q = max (m * n) (m * q)"
b63e445c8f6d lemmas about +, *, min, max on nat
haftmann
parents: 44325
diff changeset
   793
  by (simp add: max_def not_le) (auto dest: mult_left_le_imp_le mult_left_less_imp_less le_less_trans)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   794
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   795
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   796
subsubsection {* Additional theorems about @{term "op \<le>"} *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   797
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   798
text {* Complete induction, aka course-of-values induction *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   799
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   800
instance nat :: wellorder proof
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   801
  fix P and n :: nat
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   802
  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
   803
  have "\<And>q. q \<le> n \<Longrightarrow> P q"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   804
  proof (induct n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   805
    case (0 n)
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   806
    have "P 0" by (rule step) auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   807
    thus ?case using 0 by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   808
  next
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   809
    case (Suc m n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   810
    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
   811
    thus ?case
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   812
    proof
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   813
      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
   814
    next
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   815
      assume n: "n = Suc m"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   816
      show "P n"
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   817
        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
   818
    qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   819
  qed
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   820
  then show "P n" by auto
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   821
qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   822
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   823
lemma Least_Suc:
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   824
     "[| P n; ~ P 0 |] ==> (LEAST n. P n) = Suc (LEAST m. P(Suc m))"
47988
e4b69e10b990 tuned proofs;
wenzelm
parents: 47489
diff changeset
   825
  apply (cases n, auto)
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   826
  apply (frule LeastI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   827
  apply (drule_tac P = "%x. P (Suc x) " in LeastI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   828
  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
   829
  apply (erule_tac [2] Least_le)
47988
e4b69e10b990 tuned proofs;
wenzelm
parents: 47489
diff changeset
   830
  apply (cases "LEAST x. P x", auto)
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   831
  apply (drule_tac P = "%x. P (Suc x) " in Least_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   832
  apply (blast intro: order_antisym)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   833
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   834
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   835
lemma Least_Suc2:
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   836
   "[|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
   837
  apply (erule (1) Least_Suc [THEN ssubst])
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   838
  apply simp
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   839
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   840
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   841
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
   842
  apply (cases n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   843
   apply blast
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   844
  apply (rule_tac x="LEAST k. P(k)" in exI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   845
  apply (blast intro: Least_le dest: not_less_Least intro: LeastI_ex)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   846
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   847
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   848
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
   849
  unfolding One_nat_def
27823
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   850
  apply (cases n)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   851
   apply blast
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   852
  apply (frule (1) ex_least_nat_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   853
  apply (erule exE)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   854
  apply (case_tac k)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   855
   apply simp
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   856
  apply (rename_tac k1)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   857
  apply (rule_tac x=k1 in exI)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   858
  apply (auto simp add: less_eq_Suc_le)
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   859
  done
52971512d1a2 moved class wellorder to theory Orderings
haftmann
parents: 27789
diff changeset
   860
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   861
lemma nat_less_induct:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   862
  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
   863
  using assms less_induct by blast
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   864
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   865
lemma measure_induct_rule [case_names less]:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   866
  fixes f :: "'a \<Rightarrow> nat"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   867
  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
   868
  shows "P a"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   869
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
   870
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   871
text {* old style induction rules: *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   872
lemma measure_induct:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   873
  fixes f :: "'a \<Rightarrow> nat"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   874
  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
   875
  by (rule measure_induct_rule [of f P a]) iprover
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   876
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   877
lemma full_nat_induct:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   878
  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
   879
  shows "P n"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   880
  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
   881
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   882
text{*An induction rule for estabilishing binary relations*}
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   883
lemma less_Suc_induct:
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   884
  assumes less:  "i < j"
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   885
     and  step:  "!!i. P i (Suc i)"
31714
347e9d18f372 generalized less_Suc_induct
krauss
parents: 31155
diff changeset
   886
     and  trans: "!!i j k. i < j ==> j < k ==>  P i j ==> P j k ==> P i k"
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   887
  shows "P i j"
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   888
proof -
31714
347e9d18f372 generalized less_Suc_induct
krauss
parents: 31155
diff changeset
   889
  from less obtain k where j: "j = Suc (i + k)" by (auto dest: less_imp_Suc_add)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   890
  have "P i (Suc (i + k))"
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   891
  proof (induct k)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   892
    case 0
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   893
    show ?case by (simp add: step)
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   894
  next
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   895
    case (Suc k)
31714
347e9d18f372 generalized less_Suc_induct
krauss
parents: 31155
diff changeset
   896
    have "0 + i < Suc k + i" by (rule add_less_mono1) simp
347e9d18f372 generalized less_Suc_induct
krauss
parents: 31155
diff changeset
   897
    hence "i < Suc (i + k)" by (simp add: add_commute)
347e9d18f372 generalized less_Suc_induct
krauss
parents: 31155
diff changeset
   898
    from trans[OF this lessI Suc step]
347e9d18f372 generalized less_Suc_induct
krauss
parents: 31155
diff changeset
   899
    show ?case by simp
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   900
  qed
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
   901
  thus "P i j" by (simp add: j)
19870
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   902
qed
ef037d1b32d1 new results
paulson
parents: 19573
diff changeset
   903
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   904
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
   905
Provided by Roelof Oosterhuis.
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   906
$P(n)$ is true for all $n\in\mathbb{N}$ if
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   907
\begin{itemize}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   908
  \item case ``0'': given $n=0$ prove $P(n)$,
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   909
  \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
   910
        a smaller integer $m$ such that $\neg P(m)$.
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   911
\end{itemize} *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   912
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   913
text{* A compact version without explicit base case: *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   914
lemma infinite_descent:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   915
  "\<lbrakk> !!n::nat. \<not> P n \<Longrightarrow>  \<exists>m<n. \<not>  P m \<rbrakk> \<Longrightarrow>  P n"
47988
e4b69e10b990 tuned proofs;
wenzelm
parents: 47489
diff changeset
   916
by (induct n rule: less_induct) auto
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   917
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   918
lemma infinite_descent0[case_names 0 smaller]: 
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   919
  "\<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
   920
by (rule infinite_descent) (case_tac "n>0", auto)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   921
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   922
text {*
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   923
Infinite descent using a mapping to $\mathbb{N}$:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   924
$P(x)$ 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
   925
\begin{itemize}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   926
\item case ``0'': given $V(x)=0$ prove $P(x)$,
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   927
\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
   928
\end{itemize}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   929
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
   930
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   931
corollary infinite_descent0_measure [case_names 0 smaller]:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   932
  assumes A0: "!!x. V x = (0::nat) \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   933
    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
   934
  shows "P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   935
proof -
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   936
  obtain n where "n = V x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   937
  moreover have "\<And>x. V x = n \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   938
  proof (induct n rule: infinite_descent0)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   939
    case 0 -- "i.e. $V(x) = 0$"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   940
    with A0 show "P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   941
  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
   942
    case (smaller n)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   943
    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
   944
    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
   945
    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
   946
    then show ?case by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   947
  qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   948
  ultimately show "P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   949
qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   950
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   951
text{* Again, without explicit base case: *}
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   952
lemma infinite_descent_measure:
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   953
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
   954
proof -
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   955
  from assms obtain n where "n = V x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   956
  moreover have "!!x. V x = n \<Longrightarrow> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   957
  proof (induct n rule: infinite_descent, auto)
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   958
    fix x assume "\<not> P x"
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   959
    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
   960
  qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   961
  ultimately show "P x" by auto
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   962
qed
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
   963
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   964
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
   965
  monotonicity to @{text "\<le>"} monotonicity *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   966
lemma less_mono_imp_le_mono:
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   967
  "\<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
   968
by (simp add: order_le_less) (blast)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   969
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   970
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   971
text {* non-strict, in 1st argument *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   972
lemma add_le_mono1: "i \<le> j ==> i + k \<le> j + (k::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   973
by (rule add_right_mono)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   974
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   975
text {* non-strict, in both arguments *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   976
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
   977
by (rule add_mono)
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   978
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   979
lemma le_add2: "n \<le> ((m + n)::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   980
by (insert add_right_mono [of 0 m n], simp)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   981
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   982
lemma le_add1: "n \<le> ((n + m)::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   983
by (simp add: add_commute, rule le_add2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   984
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   985
lemma less_add_Suc1: "i < Suc (i + m)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   986
by (rule le_less_trans, rule le_add1, rule lessI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   987
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   988
lemma less_add_Suc2: "i < Suc (m + i)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   989
by (rule le_less_trans, rule le_add2, rule lessI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   990
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   991
lemma less_iff_Suc_add: "(m < n) = (\<exists>k. n = Suc (m + k))"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   992
by (iprover intro!: less_add_Suc1 less_imp_Suc_add)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   993
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   994
lemma trans_le_add1: "(i::nat) \<le> j ==> i \<le> j + m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   995
by (rule le_trans, assumption, rule le_add1)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   996
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
   997
lemma trans_le_add2: "(i::nat) \<le> j ==> i \<le> m + j"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
   998
by (rule le_trans, assumption, rule le_add2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
   999
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1000
lemma trans_less_add1: "(i::nat) < j ==> i < j + m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1001
by (rule less_le_trans, assumption, rule le_add1)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1002
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1003
lemma trans_less_add2: "(i::nat) < j ==> i < m + j"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1004
by (rule less_le_trans, assumption, rule le_add2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1005
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1006
lemma add_lessD1: "i + j < (k::nat) ==> i < k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1007
apply (rule le_less_trans [of _ "i+j"])
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1008
apply (simp_all add: le_add1)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1009
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1010
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1011
lemma not_add_less1 [iff]: "~ (i + j < (i::nat))"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1012
apply (rule notI)
26335
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
  1013
apply (drule add_lessD1)
961bbcc9d85b removed redundant Nat.less_not_sym, Nat.less_asym;
wenzelm
parents: 26315
diff changeset
  1014
apply (erule less_irrefl [THEN notE])
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1015
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1016
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1017
lemma not_add_less2 [iff]: "~ (j + i < (i::nat))"
26748
4d51ddd6aa5c Merged theories about wellfoundedness into one: Wellfounded.thy
krauss
parents: 26335
diff changeset
  1018
by (simp add: add_commute)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1019
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1020
lemma add_leD1: "m + k \<le> n ==> m \<le> (n::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1021
apply (rule order_trans [of _ "m+k"])
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1022
apply (simp_all add: le_add1)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1023
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1024
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1025
lemma add_leD2: "m + k \<le> n ==> k \<le> (n::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1026
apply (simp add: add_commute)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1027
apply (erule add_leD1)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1028
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1029
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1030
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
  1031
by (blast dest: add_leD1 add_leD2)
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
text {* needs @{text "!!k"} for @{text add_ac} to work *}
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1034
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
  1035
by (force simp del: add_Suc_right
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1036
    simp add: less_iff_Suc_add add_Suc_right [symmetric] add_ac)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1037
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1038
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1039
subsubsection {* More results about difference *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1040
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1041
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
  1042
  if @{term "n \<le> m"} then @{term "n + (m - n) = m"}. *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1043
lemma add_diff_inverse: "~  m < n ==> n + (m - n) = (m::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1044
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1045
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1046
lemma le_add_diff_inverse [simp]: "n \<le> m ==> n + (m - n) = (m::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1047
by (simp add: add_diff_inverse linorder_not_less)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1048
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1049
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
  1050
by (simp add: add_commute)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1051
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1052
lemma Suc_diff_le: "n \<le> m ==> Suc m - n = Suc (m - n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1053
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1054
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1055
lemma diff_less_Suc: "m - n < Suc m"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1056
apply (induct m n rule: diff_induct)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1057
apply (erule_tac [3] less_SucE)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1058
apply (simp_all add: less_Suc_eq)
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1059
done
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1060
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1061
lemma diff_le_self [simp]: "m - n \<le> (m::nat)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1062
by (induct m n rule: diff_induct) (simp_all add: le_SucI)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1063
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1064
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
  1065
  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
  1066
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1067
lemma less_imp_diff_less: "(j::nat) < k ==> j - n < k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1068
by (rule le_less_trans, rule diff_le_self)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1069
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1070
lemma diff_Suc_less [simp]: "0<n ==> n - Suc i < n"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1071
by (cases n) (auto simp add: le_simps)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1072
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1073
lemma diff_add_assoc: "k \<le> (j::nat) ==> (i + j) - k = i + (j - k)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1074
by (induct j k rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1075
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1076
lemma diff_add_assoc2: "k \<le> (j::nat) ==> (j + i) - k = (j - k) + i"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1077
by (simp add: add_commute diff_add_assoc)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1078
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1079
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
  1080
by (auto simp add: diff_add_inverse2)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1081
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1082
lemma diff_is_0_eq [simp]: "((m::nat) - n = 0) = (m \<le> n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1083
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1084
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1085
lemma diff_is_0_eq' [simp]: "m \<le> n ==> (m::nat) - n = 0"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1086
by (rule iffD2, rule diff_is_0_eq)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1087
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1088
lemma zero_less_diff [simp]: "(0 < n - (m::nat)) = (m < n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1089
by (induct m n rule: diff_induct) simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1090
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1091
lemma less_imp_add_positive:
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1092
  assumes "i < j"
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1093
  shows "\<exists>k::nat. 0 < k & i + k = j"
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1094
proof
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1095
  from assms show "0 < j - i & i + (j - i) = j"
23476
839db6346cc8 fix looping simp rule
huffman
parents: 23438
diff changeset
  1096
    by (simp add: order_less_imp_le)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1097
qed
9436
62bb04ab4b01 rearranged setup of arithmetic procedures, avoiding global reference values;
wenzelm
parents: 7702
diff changeset
  1098
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1099
text {* a nice rewrite for bounded subtraction *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1100
lemma nat_minus_add_max:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1101
  fixes n m :: nat
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1102
  shows "n - m + m = max n m"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1103
    by (simp add: max_def not_le order_less_imp_le)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1104
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1105
lemma nat_diff_split:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1106
  "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
  1107
    -- {* elimination of @{text -} on @{text nat} *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1108
by (cases "a < b")
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1109
  (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
  1110
    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
  1111
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1112
lemma nat_diff_split_asm:
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1113
  "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
  1114
    -- {* elimination of @{text -} on @{text nat} in assumptions *}
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1115
by (auto split: nat_diff_split)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1116
47255
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1117
lemma Suc_pred': "0 < n ==> n = Suc(n - 1)"
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1118
  by simp
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1119
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1120
lemma add_eq_if: "(m::nat) + n = (if m=0 then n else Suc ((m - 1) + n))"
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1121
  unfolding One_nat_def by (cases m) simp_all
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1122
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1123
lemma mult_eq_if: "(m::nat) * n = (if m=0 then 0 else n + ((m - 1) * n))"
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1124
  unfolding One_nat_def by (cases m) simp_all
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1125
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1126
lemma Suc_diff_eq_diff_pred: "0 < n ==> Suc m - n = m - (n - 1)"
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1127
  unfolding One_nat_def by (cases n) simp_all
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1128
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1129
lemma diff_Suc_eq_diff_pred: "m - Suc n = (m - 1) - n"
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1130
  unfolding One_nat_def by (cases m) simp_all
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1131
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1132
lemma Let_Suc [simp]: "Let (Suc n) f == f (Suc n)"
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1133
  by (fact Let_def)
30a1692557b0 removed Nat_Numeral.thy, moving all theorems elsewhere
huffman
parents: 47208
diff changeset
  1134
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1135
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1136
subsubsection {* Monotonicity of Multiplication *}
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1137
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1138
lemma mult_le_mono1: "i \<le> (j::nat) ==> i * k \<le> j * k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1139
by (simp add: mult_right_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1140
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1141
lemma mult_le_mono2: "i \<le> (j::nat) ==> k * i \<le> k * j"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1142
by (simp add: mult_left_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1143
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1144
text {* @{text "\<le>"} monotonicity, BOTH arguments *}
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1145
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
  1146
by (simp add: mult_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1147
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1148
lemma mult_less_mono1: "(i::nat) < j ==> 0 < k ==> i * k < j * k"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1149
by (simp add: mult_strict_right_mono)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1150
14266
08b34c902618 conversion of integers to use Ring_and_Field;
paulson
parents: 14265
diff changeset
  1151
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
  1152
      there are no negative numbers.*}
08b34c902618 conversion of integers to use Ring_and_Field;
paulson
parents: 14265
diff changeset
  1153
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
  1154
  apply (induct m)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1155
   apply simp
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1156
  apply (case_tac n)
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1157
   apply simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1158
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1159
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
  1160
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
  1161
  apply (induct m)
22718
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1162
   apply simp
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1163
  apply (case_tac n)
936f7580937d tuned proofs;
wenzelm
parents: 22483
diff changeset
  1164
   apply simp_all
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1165
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1166
14341
a09441bd4f1e Ring_and_Field now requires axiom add_left_imp_eq for semirings.
paulson
parents: 14331
diff changeset
  1167
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
  1168
  apply (safe intro!: mult_less_mono1)
47988
e4b69e10b990 tuned proofs;
wenzelm
parents: 47489
diff changeset
  1169
  apply (cases k, auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1170
  apply (simp del: le_0_eq add: linorder_not_le [symmetric])
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1171
  apply (blast intro: mult_le_mono1)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1172
  done
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1173
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1174
lemma mult_less_cancel1 [simp]: "(k * (m::nat) < k * n) = (0 < k & m < n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1175
by (simp add: mult_commute [of k])
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1176
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1177
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
  1178
by (simp add: linorder_not_less [symmetric], auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1179
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1180
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
  1181
by (simp add: linorder_not_less [symmetric], auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1182
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1183
lemma Suc_mult_less_cancel1: "(Suc k * m < Suc k * n) = (m < n)"
24438
2d8058804a76 Added infinite_descent
nipkow
parents: 24286
diff changeset
  1184
by (subst mult_less_cancel1) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1185
14267
b963e9cee2a0 More refinements to Ring_and_Field and numerics. Conversion of Divides_lemmas
paulson
parents: 14266
diff changeset
  1186
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
  1187
by (subst mult_le_cancel1) simp
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1188
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1189
lemma le_square: "m \<le> m * (m::nat)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1190
  by (cases m) (auto intro: le_add1)
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1191
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1192
lemma le_cube: "(m::nat) \<le> m * (m * m)"
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1193
  by (cases m) (auto intro: le_add1)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1194
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1195
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
  1196
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
  1197
  apply (drule sym)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1198
  apply (rule disjCI)
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1199
  apply (rule nat_less_cases, erule_tac [2] _)
25157
8b80535cd017 random tidying of proofs
paulson
parents: 25145
diff changeset
  1200
   apply (drule_tac [2] mult_less_mono2)
25162
ad4d5365d9d8 went back to >0
nipkow
parents: 25157
diff changeset
  1201
    apply (auto)
13449
43c9ec498291 - Converted to new theory format
berghofe
parents: 12338
diff changeset
  1202
  done
9436
62bb04ab4b01 rearranged setup of arithmetic procedures, avoiding global reference values;
wenzelm
parents: 7702
diff changeset
  1203
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1204
text {* the lattice order on @{typ nat} *}
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1205
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1206
instantiation nat :: distrib_lattice
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1207
begin
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1208
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1209
definition
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1210
  "(inf \<Colon> nat \<Rightarrow> nat \<Rightarrow> nat) = min"
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1211
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1212
definition
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1213
  "(sup \<Colon> nat \<Rightarrow> nat \<Rightarrow> nat) = max"
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1214
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1215
instance by intro_classes
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1216
  (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
  1217
    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
  1218
26072
f65a7fa2da6c <= and < on nat no longer depend on wellfounded relations
haftmann
parents: 25928
diff changeset
  1219
end
24995
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1220
c26e0166e568 refined; moved class power to theory Power
haftmann
parents: 24729
diff changeset
  1221
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1222
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
  1223
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1224
text {*
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1225
  We use the same logical constant for the power operations on
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1226
  functions and relations, in order to share the same syntax.
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1227
*}
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1228
45965
2af982715e5c generalized type signature to permit overloading on `set`
haftmann
parents: 45933
diff changeset
  1229
consts compow :: "nat \<Rightarrow> 'a \<Rightarrow> 'a"
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1230
45965
2af982715e5c generalized type signature to permit overloading on `set`
haftmann
parents: 45933
diff changeset
  1231
abbreviation compower :: "'a \<Rightarrow> nat \<Rightarrow> 'a" (infixr "^^" 80) where
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1232
  "f ^^ n \<equiv> compow n f"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1233
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1234
notation (latex output)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1235
  compower ("(_\<^bsup>_\<^esup>)" [1000] 1000)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1236
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1237
notation (HTML output)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1238
  compower ("(_\<^bsup>_\<^esup>)" [1000] 1000)
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1239
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1240
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
  1241
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1242
overloading
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1243
  funpow == "compow :: nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> ('a \<Rightarrow> 'a)"
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1244
begin
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1245
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1246
primrec funpow :: "nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'a" where
44325
84696670feb1 more uniform formatting of specifications
haftmann
parents: 44278
diff changeset
  1247
  "funpow 0 f = id"
84696670feb1 more uniform formatting of specifications
haftmann
parents: 44278
diff changeset
  1248
| "funpow (Suc n) f = f o funpow n f"
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1249
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1250
end
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1251
49723
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1252
lemma funpow_Suc_right:
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1253
  "f ^^ Suc n = f ^^ n \<circ> f"
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1254
proof (induct n)
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1255
  case 0 then show ?case by simp
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1256
next
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1257
  fix n
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1258
  assume "f ^^ Suc n = f ^^ n \<circ> f"
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1259
  then show "f ^^ Suc (Suc n) = f ^^ Suc n \<circ> f"
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1260
    by (simp add: o_assoc)
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1261
qed
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1262
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1263
lemmas funpow_simps_right = funpow.simps(1) funpow_Suc_right
bbc2942ba09f alternative simplification of ^^ to the righthand side;
haftmann
parents: 49388
diff changeset
  1264
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1265
text {* for code generation *}
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1266
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1267
definition funpow :: "nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'a" where
46028
9f113cdf3d66 attribute code_abbrev superseedes code_unfold_post
haftmann
parents: 45965
diff changeset
  1268
  funpow_code_def [code_abbrev]: "funpow = compow"
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1269
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1270
lemma [code]:
37430
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1271
  "funpow (Suc n) f = f o funpow n f"
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1272
  "funpow 0 f = id"
37430
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1273
  by (simp_all add: funpow_code_def)
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1274
36176
3fe7e97ccca8 replaced generic 'hide' command by more conventional 'hide_class', 'hide_type', 'hide_const', 'hide_fact' -- frees some popular keywords;
wenzelm
parents: 35828
diff changeset
  1275
hide_const (open) funpow
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1276
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1277
lemma funpow_add:
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1278
  "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
  1279
  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
  1280
37430
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1281
lemma funpow_mult:
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1282
  fixes f :: "'a \<Rightarrow> 'a"
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1283
  shows "(f ^^ m) ^^ n = f ^^ (m * n)"
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1284
  by (induct n) (simp_all add: funpow_add)
a77740fc3957 added lemma funpow_mult
haftmann
parents: 37387
diff changeset
  1285
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1286
lemma funpow_swap1:
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1287
  "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
  1288
proof -
30971
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1289
  have "f ((f ^^ n) x) = (f ^^ (n + 1)) x" by simp
7fbebf75b3ef funpow and relpow with shared "^^" syntax
haftmann
parents: 30966
diff changeset
  1290
  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
  1291
  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
  1292
  finally show ?thesis .
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1293
qed
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1294
38621
d6cb7e625d75 more concise characterization of of_nat operation and class semiring_char_0
haftmann
parents: 37767
diff changeset
  1295
lemma comp_funpow:
d6cb7e625d75 more concise characterization of of_nat operation and class semiring_char_0
haftmann
parents: 37767
diff changeset
  1296
  fixes f :: "'a \<Rightarrow> 'a"
d6cb7e625d75 more concise characterization of of_nat operation and class semiring_char_0
haftmann
parents: 37767
diff changeset
  1297
  shows "comp f ^^ n = comp (f ^^ n)"
d6cb7e625d75 more concise characterization of of_nat operation and class semiring_char_0
haftmann
parents: 37767
diff changeset
  1298
  by (induct n) simp_all
30954
cf50e67bc1d1 power operation on functions in theory Nat; power operation on relations in theory Transitive_Closure
haftmann
parents: 30686
diff changeset
  1299
38621
d6cb7e625d75 more concise characterization of of_nat operation and class semiring_char_0
haftmann
parents: 37767
diff changeset
  1300
45833
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1301
subsection {* Kleene iteration *}
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1302
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1303
lemma Kleene_iter_lpfp: assumes "mono f" and "f p \<le> p" shows "(f^^k) bot \<le> p"
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1304
proof(induction k)
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1305
  case 0 show ?case by simp
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1306
next
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1307
  case Suc
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1308
  from monoD[OF assms(1) Suc] assms(2)
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1309
  show ?case by simp
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1310
qed
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1311
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1312
lemma lfp_Kleene_iter: assumes "mono f" and "(f^^Suc k) bot = (f^^k) bot"
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1313
shows "lfp f = (f^^k) bot"
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1314
proof(rule antisym)
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1315
  show "lfp f \<le> (f^^k) bot"
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1316
  proof(rule lfp_lowerbound)
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset
  1317
    show "f ((f^^k) bot) \<le> (f^^k) bot" using assms(2) by simp
033cb3a668b9 lemmas about Kleene iteration
nipkow
parents: 45696
diff changeset