author | haftmann |
Fri, 18 Jul 2008 18:25:53 +0200 | |
changeset 27651 | 16a26996c30e |
parent 26342 | 0f65fa163304 |
child 28229 | 4f06fae6a55e |
permissions | -rw-r--r-- |
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(* Title: HOL/NatBin.thy |
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ID: $Id$ |
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Author: Lawrence C Paulson, Cambridge University Computer Laboratory |
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Copyright 1999 University of Cambridge |
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*) |
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header {* Binary arithmetic for the natural numbers *} |
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theory NatBin |
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imports IntDiv |
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begin |
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text {* |
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Arithmetic for naturals is reduced to that for the non-negative integers. |
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*} |
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instantiation nat :: number |
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begin |
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definition |
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nat_number_of_def [code inline]: "number_of v = nat (number_of v)" |
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instance .. |
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end |
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lemma [code post]: |
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"nat (number_of v) = number_of v" |
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unfolding nat_number_of_def .. |
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abbreviation (xsymbols) |
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square :: "'a::power => 'a" ("(_\<twosuperior>)" [1000] 999) where |
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"x\<twosuperior> == x^2" |
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notation (latex output) |
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square ("(_\<twosuperior>)" [1000] 999) |
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notation (HTML output) |
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square ("(_\<twosuperior>)" [1000] 999) |
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subsection{*Function @{term nat}: Coercion from Type @{typ int} to @{typ nat}*} |
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declare nat_0 [simp] nat_1 [simp] |
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lemma nat_number_of [simp]: "nat (number_of w) = number_of w" |
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by (simp add: nat_number_of_def) |
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lemma nat_numeral_0_eq_0 [simp]: "Numeral0 = (0::nat)" |
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by (simp add: nat_number_of_def) |
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lemma nat_numeral_1_eq_1 [simp]: "Numeral1 = (1::nat)" |
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by (simp add: nat_1 nat_number_of_def) |
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lemma numeral_1_eq_Suc_0: "Numeral1 = Suc 0" |
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by (simp add: nat_numeral_1_eq_1) |
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lemma numeral_2_eq_2: "2 = Suc (Suc 0)" |
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apply (unfold nat_number_of_def) |
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apply (rule nat_2) |
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done |
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text{*Distributive laws for type @{text nat}. The others are in theory |
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@{text IntArith}, but these require div and mod to be defined for type |
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"int". They also need some of the lemmas proved above.*} |
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lemma nat_div_distrib: "(0::int) <= z ==> nat (z div z') = nat z div nat z'" |
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apply (case_tac "0 <= z'") |
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apply (auto simp add: div_nonneg_neg_le0) |
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apply (case_tac "z' = 0", simp) |
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apply (auto elim!: nonneg_eq_int) |
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apply (rename_tac m m') |
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apply (subgoal_tac "0 <= int m div int m'") |
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prefer 2 apply (simp add: nat_numeral_0_eq_0 pos_imp_zdiv_nonneg_iff) |
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apply (rule of_nat_eq_iff [where 'a=int, THEN iffD1], simp) |
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apply (rule_tac r = "int (m mod m') " in quorem_div) |
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prefer 2 apply force |
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apply (simp add: nat_less_iff [symmetric] quorem_def nat_numeral_0_eq_0 |
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of_nat_add [symmetric] of_nat_mult [symmetric] |
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del: of_nat_add of_nat_mult) |
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done |
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(*Fails if z'<0: the LHS collapses to (nat z) but the RHS doesn't*) |
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lemma nat_mod_distrib: |
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"[| (0::int) <= z; 0 <= z' |] ==> nat (z mod z') = nat z mod nat z'" |
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apply (case_tac "z' = 0", simp add: DIVISION_BY_ZERO) |
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apply (auto elim!: nonneg_eq_int) |
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apply (rename_tac m m') |
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apply (subgoal_tac "0 <= int m mod int m'") |
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prefer 2 apply (simp add: nat_less_iff nat_numeral_0_eq_0 pos_mod_sign) |
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apply (rule int_int_eq [THEN iffD1], simp) |
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apply (rule_tac q = "int (m div m') " in quorem_mod) |
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prefer 2 apply force |
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apply (simp add: nat_less_iff [symmetric] quorem_def nat_numeral_0_eq_0 |
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of_nat_add [symmetric] of_nat_mult [symmetric] |
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del: of_nat_add of_nat_mult) |
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done |
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text{*Suggested by Matthias Daum*} |
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lemma int_div_less_self: "\<lbrakk>0 < x; 1 < k\<rbrakk> \<Longrightarrow> x div k < (x::int)" |
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apply (subgoal_tac "nat x div nat k < nat x") |
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apply (simp (asm_lr) add: nat_div_distrib [symmetric]) |
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apply (rule Divides.div_less_dividend, simp_all) |
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done |
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subsection{*Function @{term int}: Coercion from Type @{typ nat} to @{typ int}*} |
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(*"neg" is used in rewrite rules for binary comparisons*) |
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lemma int_nat_number_of [simp]: |
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"int (number_of v) = |
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(if neg (number_of v :: int) then 0 |
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else (number_of v :: int))" |
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by (simp del: nat_number_of |
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add: neg_nat nat_number_of_def not_neg_nat add_assoc) |
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subsubsection{*Successor *} |
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lemma Suc_nat_eq_nat_zadd1: "(0::int) <= z ==> Suc (nat z) = nat (1 + z)" |
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apply (rule sym) |
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apply (simp add: nat_eq_iff int_Suc) |
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done |
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lemma Suc_nat_number_of_add: |
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"Suc (number_of v + n) = |
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(if neg (number_of v :: int) then 1+n else number_of (Int.succ v) + n)" |
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by (simp del: nat_number_of |
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add: nat_number_of_def neg_nat |
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Suc_nat_eq_nat_zadd1 number_of_succ) |
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lemma Suc_nat_number_of [simp]: |
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"Suc (number_of v) = |
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(if neg (number_of v :: int) then 1 else number_of (Int.succ v))" |
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apply (cut_tac n = 0 in Suc_nat_number_of_add) |
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apply (simp cong del: if_weak_cong) |
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done |
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subsubsection{*Addition *} |
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(*"neg" is used in rewrite rules for binary comparisons*) |
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lemma add_nat_number_of [simp]: |
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"(number_of v :: nat) + number_of v' = |
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(if neg (number_of v :: int) then number_of v' |
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else if neg (number_of v' :: int) then number_of v |
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else number_of (v + v'))" |
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by (simp add: neg_nat nat_number_of_def nat_add_distrib [symmetric] del: nat_number_of) |
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subsubsection{*Subtraction *} |
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lemma diff_nat_eq_if: |
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"nat z - nat z' = |
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(if neg z' then nat z |
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else let d = z-z' in |
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if neg d then 0 else nat d)" |
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by (simp add: Let_def nat_diff_distrib [symmetric] neg_eq_less_0 not_neg_eq_ge_0) |
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lemma diff_nat_number_of [simp]: |
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"(number_of v :: nat) - number_of v' = |
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(if neg (number_of v' :: int) then number_of v |
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else let d = number_of (v + uminus v') in |
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if neg d then 0 else nat d)" |
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by (simp del: nat_number_of add: diff_nat_eq_if nat_number_of_def) |
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subsubsection{*Multiplication *} |
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lemma mult_nat_number_of [simp]: |
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"(number_of v :: nat) * number_of v' = |
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(if neg (number_of v :: int) then 0 else number_of (v * v'))" |
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by (simp add: neg_nat nat_number_of_def nat_mult_distrib [symmetric] del: nat_number_of) |
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subsubsection{*Quotient *} |
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lemma div_nat_number_of [simp]: |
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"(number_of v :: nat) div number_of v' = |
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(if neg (number_of v :: int) then 0 |
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else nat (number_of v div number_of v'))" |
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by (simp add: neg_nat nat_number_of_def nat_div_distrib [symmetric] del: nat_number_of) |
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lemma one_div_nat_number_of [simp]: |
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"Suc 0 div number_of v' = nat (1 div number_of v')" |
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by (simp del: nat_numeral_1_eq_1 add: numeral_1_eq_Suc_0 [symmetric]) |
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subsubsection{*Remainder *} |
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lemma mod_nat_number_of [simp]: |
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"(number_of v :: nat) mod number_of v' = |
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(if neg (number_of v :: int) then 0 |
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else if neg (number_of v' :: int) then number_of v |
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else nat (number_of v mod number_of v'))" |
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by (simp add: neg_nat nat_number_of_def nat_mod_distrib [symmetric] del: nat_number_of) |
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lemma one_mod_nat_number_of [simp]: |
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"Suc 0 mod number_of v' = |
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(if neg (number_of v' :: int) then Suc 0 |
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else nat (1 mod number_of v'))" |
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by (simp del: nat_numeral_1_eq_1 add: numeral_1_eq_Suc_0 [symmetric]) |
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subsubsection{* Divisibility *} |
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lemmas dvd_eq_mod_eq_0_number_of = |
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dvd_eq_mod_eq_0 [of "number_of x" "number_of y", standard] |
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declare dvd_eq_mod_eq_0_number_of [simp] |
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ML |
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{* |
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val nat_number_of_def = thm"nat_number_of_def"; |
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val nat_number_of = thm"nat_number_of"; |
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val nat_numeral_0_eq_0 = thm"nat_numeral_0_eq_0"; |
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val nat_numeral_1_eq_1 = thm"nat_numeral_1_eq_1"; |
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val numeral_1_eq_Suc_0 = thm"numeral_1_eq_Suc_0"; |
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val numeral_2_eq_2 = thm"numeral_2_eq_2"; |
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val nat_div_distrib = thm"nat_div_distrib"; |
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val nat_mod_distrib = thm"nat_mod_distrib"; |
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val int_nat_number_of = thm"int_nat_number_of"; |
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val Suc_nat_eq_nat_zadd1 = thm"Suc_nat_eq_nat_zadd1"; |
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val Suc_nat_number_of_add = thm"Suc_nat_number_of_add"; |
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val Suc_nat_number_of = thm"Suc_nat_number_of"; |
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val add_nat_number_of = thm"add_nat_number_of"; |
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val diff_nat_eq_if = thm"diff_nat_eq_if"; |
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val diff_nat_number_of = thm"diff_nat_number_of"; |
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val mult_nat_number_of = thm"mult_nat_number_of"; |
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val div_nat_number_of = thm"div_nat_number_of"; |
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val mod_nat_number_of = thm"mod_nat_number_of"; |
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*} |
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subsection{*Comparisons*} |
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subsubsection{*Equals (=) *} |
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lemma eq_nat_nat_iff: |
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"[| (0::int) <= z; 0 <= z' |] ==> (nat z = nat z') = (z=z')" |
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by (auto elim!: nonneg_eq_int) |
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(*"neg" is used in rewrite rules for binary comparisons*) |
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lemma eq_nat_number_of [simp]: |
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"((number_of v :: nat) = number_of v') = |
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(if neg (number_of v :: int) then (iszero (number_of v' :: int) | neg (number_of v' :: int)) |
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else if neg (number_of v' :: int) then iszero (number_of v :: int) |
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else iszero (number_of (v + uminus v') :: int))" |
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apply (simp only: simp_thms neg_nat not_neg_eq_ge_0 nat_number_of_def |
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eq_nat_nat_iff eq_number_of_eq nat_0 iszero_def |
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split add: split_if cong add: imp_cong) |
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apply (simp only: nat_eq_iff nat_eq_iff2) |
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apply (simp add: not_neg_eq_ge_0 [symmetric]) |
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done |
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subsubsection{*Less-than (<) *} |
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(*"neg" is used in rewrite rules for binary comparisons*) |
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lemma less_nat_number_of [simp]: |
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"((number_of v :: nat) < number_of v') = |
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(if neg (number_of v :: int) then neg (number_of (uminus v') :: int) |
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else neg (number_of (v + uminus v') :: int))" |
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by (simp only: simp_thms neg_nat not_neg_eq_ge_0 nat_number_of_def |
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nat_less_eq_zless less_number_of_eq_neg zless_nat_eq_int_zless |
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cong add: imp_cong, simp add: Pls_def) |
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(*Maps #n to n for n = 0, 1, 2*) |
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lemmas numerals = nat_numeral_0_eq_0 nat_numeral_1_eq_1 numeral_2_eq_2 |
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subsection{*Powers with Numeric Exponents*} |
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text{*We cannot refer to the number @{term 2} in @{text Ring_and_Field.thy}. |
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We cannot prove general results about the numeral @{term "-1"}, so we have to |
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use @{term "- 1"} instead.*} |
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lemma power2_eq_square: "(a::'a::recpower)\<twosuperior> = a * a" |
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by (simp add: numeral_2_eq_2 Power.power_Suc) |
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lemma zero_power2 [simp]: "(0::'a::{semiring_1,recpower})\<twosuperior> = 0" |
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by (simp add: power2_eq_square) |
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lemma one_power2 [simp]: "(1::'a::{semiring_1,recpower})\<twosuperior> = 1" |
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by (simp add: power2_eq_square) |
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lemma power3_eq_cube: "(x::'a::recpower) ^ 3 = x * x * x" |
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apply (subgoal_tac "3 = Suc (Suc (Suc 0))") |
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apply (erule ssubst) |
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apply (simp add: power_Suc mult_ac) |
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apply (unfold nat_number_of_def) |
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apply (subst nat_eq_iff) |
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apply simp |
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done |
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text{*Squares of literal numerals will be evaluated.*} |
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lemmas power2_eq_square_number_of = |
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power2_eq_square [of "number_of w", standard] |
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declare power2_eq_square_number_of [simp] |
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lemma zero_le_power2[simp]: "0 \<le> (a\<twosuperior>::'a::{ordered_idom,recpower})" |
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by (simp add: power2_eq_square) |
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lemma zero_less_power2[simp]: |
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"(0 < a\<twosuperior>) = (a \<noteq> (0::'a::{ordered_idom,recpower}))" |
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by (force simp add: power2_eq_square zero_less_mult_iff linorder_neq_iff) |
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lemma power2_less_0[simp]: |
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fixes a :: "'a::{ordered_idom,recpower}" |
|
315 |
shows "~ (a\<twosuperior> < 0)" |
|
316 |
by (force simp add: power2_eq_square mult_less_0_iff) |
|
317 |
||
318 |
lemma zero_eq_power2[simp]: |
|
319 |
"(a\<twosuperior> = 0) = (a = (0::'a::{ordered_idom,recpower}))" |
|
320 |
by (force simp add: power2_eq_square mult_eq_0_iff) |
|
321 |
||
322 |
lemma abs_power2[simp]: |
|
323 |
"abs(a\<twosuperior>) = (a\<twosuperior>::'a::{ordered_idom,recpower})" |
|
324 |
by (simp add: power2_eq_square abs_mult abs_mult_self) |
|
325 |
||
326 |
lemma power2_abs[simp]: |
|
327 |
"(abs a)\<twosuperior> = (a\<twosuperior>::'a::{ordered_idom,recpower})" |
|
328 |
by (simp add: power2_eq_square abs_mult_self) |
|
329 |
||
330 |
lemma power2_minus[simp]: |
|
331 |
"(- a)\<twosuperior> = (a\<twosuperior>::'a::{comm_ring_1,recpower})" |
|
332 |
by (simp add: power2_eq_square) |
|
333 |
||
334 |
lemma power2_le_imp_le: |
|
335 |
fixes x y :: "'a::{ordered_semidom,recpower}" |
|
336 |
shows "\<lbrakk>x\<twosuperior> \<le> y\<twosuperior>; 0 \<le> y\<rbrakk> \<Longrightarrow> x \<le> y" |
|
337 |
unfolding numeral_2_eq_2 by (rule power_le_imp_le_base) |
|
338 |
||
339 |
lemma power2_less_imp_less: |
|
340 |
fixes x y :: "'a::{ordered_semidom,recpower}" |
|
341 |
shows "\<lbrakk>x\<twosuperior> < y\<twosuperior>; 0 \<le> y\<rbrakk> \<Longrightarrow> x < y" |
|
342 |
by (rule power_less_imp_less_base) |
|
343 |
||
344 |
lemma power2_eq_imp_eq: |
|
345 |
fixes x y :: "'a::{ordered_semidom,recpower}" |
|
346 |
shows "\<lbrakk>x\<twosuperior> = y\<twosuperior>; 0 \<le> x; 0 \<le> y\<rbrakk> \<Longrightarrow> x = y" |
|
347 |
unfolding numeral_2_eq_2 by (erule (2) power_eq_imp_eq_base, simp) |
|
348 |
||
349 |
lemma power_minus1_even[simp]: "(- 1) ^ (2*n) = (1::'a::{comm_ring_1,recpower})" |
|
350 |
apply (induct "n") |
|
351 |
apply (auto simp add: power_Suc power_add) |
|
352 |
done |
|
353 |
||
354 |
lemma power_even_eq: "(a::'a::recpower) ^ (2*n) = (a^n)^2" |
|
355 |
by (subst mult_commute) (simp add: power_mult) |
|
356 |
||
357 |
lemma power_odd_eq: "(a::int) ^ Suc(2*n) = a * (a^n)^2" |
|
358 |
by (simp add: power_even_eq) |
|
359 |
||
360 |
lemma power_minus_even [simp]: |
|
361 |
"(-a) ^ (2*n) = (a::'a::{comm_ring_1,recpower}) ^ (2*n)" |
|
362 |
by (simp add: power_minus1_even power_minus [of a]) |
|
363 |
||
364 |
lemma zero_le_even_power'[simp]: |
|
365 |
"0 \<le> (a::'a::{ordered_idom,recpower}) ^ (2*n)" |
|
366 |
proof (induct "n") |
|
367 |
case 0 |
|
368 |
show ?case by (simp add: zero_le_one) |
|
369 |
next |
|
370 |
case (Suc n) |
|
371 |
have "a ^ (2 * Suc n) = (a*a) * a ^ (2*n)" |
|
372 |
by (simp add: mult_ac power_add power2_eq_square) |
|
373 |
thus ?case |
|
374 |
by (simp add: prems zero_le_mult_iff) |
|
375 |
qed |
|
376 |
||
377 |
lemma odd_power_less_zero: |
|
378 |
"(a::'a::{ordered_idom,recpower}) < 0 ==> a ^ Suc(2*n) < 0" |
|
379 |
proof (induct "n") |
|
380 |
case 0 |
|
23389 | 381 |
then show ?case by (simp add: Power.power_Suc) |
23164 | 382 |
next |
383 |
case (Suc n) |
|
23389 | 384 |
have "a ^ Suc (2 * Suc n) = (a*a) * a ^ Suc(2*n)" |
385 |
by (simp add: mult_ac power_add power2_eq_square Power.power_Suc) |
|
386 |
thus ?case |
|
387 |
by (simp add: prems mult_less_0_iff mult_neg_neg) |
|
23164 | 388 |
qed |
389 |
||
390 |
lemma odd_0_le_power_imp_0_le: |
|
391 |
"0 \<le> a ^ Suc(2*n) ==> 0 \<le> (a::'a::{ordered_idom,recpower})" |
|
392 |
apply (insert odd_power_less_zero [of a n]) |
|
393 |
apply (force simp add: linorder_not_less [symmetric]) |
|
394 |
done |
|
395 |
||
396 |
text{*Simprules for comparisons where common factors can be cancelled.*} |
|
397 |
lemmas zero_compare_simps = |
|
398 |
add_strict_increasing add_strict_increasing2 add_increasing |
|
399 |
zero_le_mult_iff zero_le_divide_iff |
|
400 |
zero_less_mult_iff zero_less_divide_iff |
|
401 |
mult_le_0_iff divide_le_0_iff |
|
402 |
mult_less_0_iff divide_less_0_iff |
|
403 |
zero_le_power2 power2_less_0 |
|
404 |
||
405 |
subsubsection{*Nat *} |
|
406 |
||
407 |
lemma Suc_pred': "0 < n ==> n = Suc(n - 1)" |
|
408 |
by (simp add: numerals) |
|
409 |
||
410 |
(*Expresses a natural number constant as the Suc of another one. |
|
411 |
NOT suitable for rewriting because n recurs in the condition.*) |
|
412 |
lemmas expand_Suc = Suc_pred' [of "number_of v", standard] |
|
413 |
||
414 |
subsubsection{*Arith *} |
|
415 |
||
416 |
lemma Suc_eq_add_numeral_1: "Suc n = n + 1" |
|
417 |
by (simp add: numerals) |
|
418 |
||
419 |
lemma Suc_eq_add_numeral_1_left: "Suc n = 1 + n" |
|
420 |
by (simp add: numerals) |
|
421 |
||
422 |
(* These two can be useful when m = number_of... *) |
|
423 |
||
424 |
lemma add_eq_if: "(m::nat) + n = (if m=0 then n else Suc ((m - 1) + n))" |
|
425 |
apply (case_tac "m") |
|
426 |
apply (simp_all add: numerals) |
|
427 |
done |
|
428 |
||
429 |
lemma mult_eq_if: "(m::nat) * n = (if m=0 then 0 else n + ((m - 1) * n))" |
|
430 |
apply (case_tac "m") |
|
431 |
apply (simp_all add: numerals) |
|
432 |
done |
|
433 |
||
434 |
lemma power_eq_if: "(p ^ m :: nat) = (if m=0 then 1 else p * (p ^ (m - 1)))" |
|
435 |
apply (case_tac "m") |
|
436 |
apply (simp_all add: numerals) |
|
437 |
done |
|
438 |
||
439 |
||
440 |
subsection{*Comparisons involving (0::nat) *} |
|
441 |
||
442 |
text{*Simplification already does @{term "n<0"}, @{term "n\<le>0"} and @{term "0\<le>n"}.*} |
|
443 |
||
444 |
lemma eq_number_of_0 [simp]: |
|
445 |
"(number_of v = (0::nat)) = |
|
446 |
(if neg (number_of v :: int) then True else iszero (number_of v :: int))" |
|
447 |
by (simp del: nat_numeral_0_eq_0 add: nat_numeral_0_eq_0 [symmetric] iszero_0) |
|
448 |
||
449 |
lemma eq_0_number_of [simp]: |
|
450 |
"((0::nat) = number_of v) = |
|
451 |
(if neg (number_of v :: int) then True else iszero (number_of v :: int))" |
|
452 |
by (rule trans [OF eq_sym_conv eq_number_of_0]) |
|
453 |
||
454 |
lemma less_0_number_of [simp]: |
|
455 |
"((0::nat) < number_of v) = neg (number_of (uminus v) :: int)" |
|
456 |
by (simp del: nat_numeral_0_eq_0 add: nat_numeral_0_eq_0 [symmetric] Pls_def) |
|
457 |
||
458 |
||
459 |
lemma neg_imp_number_of_eq_0: "neg (number_of v :: int) ==> number_of v = (0::nat)" |
|
460 |
by (simp del: nat_numeral_0_eq_0 add: nat_numeral_0_eq_0 [symmetric] iszero_0) |
|
461 |
||
462 |
||
463 |
||
464 |
subsection{*Comparisons involving @{term Suc} *} |
|
465 |
||
466 |
lemma eq_number_of_Suc [simp]: |
|
467 |
"(number_of v = Suc n) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
468 |
(let pv = number_of (Int.pred v) in |
23164 | 469 |
if neg pv then False else nat pv = n)" |
470 |
apply (simp only: simp_thms Let_def neg_eq_less_0 linorder_not_less |
|
471 |
number_of_pred nat_number_of_def |
|
472 |
split add: split_if) |
|
473 |
apply (rule_tac x = "number_of v" in spec) |
|
474 |
apply (auto simp add: nat_eq_iff) |
|
475 |
done |
|
476 |
||
477 |
lemma Suc_eq_number_of [simp]: |
|
478 |
"(Suc n = number_of v) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
479 |
(let pv = number_of (Int.pred v) in |
23164 | 480 |
if neg pv then False else nat pv = n)" |
481 |
by (rule trans [OF eq_sym_conv eq_number_of_Suc]) |
|
482 |
||
483 |
lemma less_number_of_Suc [simp]: |
|
484 |
"(number_of v < Suc n) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
485 |
(let pv = number_of (Int.pred v) in |
23164 | 486 |
if neg pv then True else nat pv < n)" |
487 |
apply (simp only: simp_thms Let_def neg_eq_less_0 linorder_not_less |
|
488 |
number_of_pred nat_number_of_def |
|
489 |
split add: split_if) |
|
490 |
apply (rule_tac x = "number_of v" in spec) |
|
491 |
apply (auto simp add: nat_less_iff) |
|
492 |
done |
|
493 |
||
494 |
lemma less_Suc_number_of [simp]: |
|
495 |
"(Suc n < number_of v) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
496 |
(let pv = number_of (Int.pred v) in |
23164 | 497 |
if neg pv then False else n < nat pv)" |
498 |
apply (simp only: simp_thms Let_def neg_eq_less_0 linorder_not_less |
|
499 |
number_of_pred nat_number_of_def |
|
500 |
split add: split_if) |
|
501 |
apply (rule_tac x = "number_of v" in spec) |
|
502 |
apply (auto simp add: zless_nat_eq_int_zless) |
|
503 |
done |
|
504 |
||
505 |
lemma le_number_of_Suc [simp]: |
|
506 |
"(number_of v <= Suc n) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
507 |
(let pv = number_of (Int.pred v) in |
23164 | 508 |
if neg pv then True else nat pv <= n)" |
509 |
by (simp add: Let_def less_Suc_number_of linorder_not_less [symmetric]) |
|
510 |
||
511 |
lemma le_Suc_number_of [simp]: |
|
512 |
"(Suc n <= number_of v) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
513 |
(let pv = number_of (Int.pred v) in |
23164 | 514 |
if neg pv then False else n <= nat pv)" |
515 |
by (simp add: Let_def less_number_of_Suc linorder_not_less [symmetric]) |
|
516 |
||
517 |
||
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
518 |
lemma eq_number_of_Pls_Min: "(Numeral0 ::int) ~= number_of Int.Min" |
23164 | 519 |
by auto |
520 |
||
521 |
||
522 |
||
523 |
subsection{*Max and Min Combined with @{term Suc} *} |
|
524 |
||
525 |
lemma max_number_of_Suc [simp]: |
|
526 |
"max (Suc n) (number_of v) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
527 |
(let pv = number_of (Int.pred v) in |
23164 | 528 |
if neg pv then Suc n else Suc(max n (nat pv)))" |
529 |
apply (simp only: Let_def neg_eq_less_0 number_of_pred nat_number_of_def |
|
530 |
split add: split_if nat.split) |
|
531 |
apply (rule_tac x = "number_of v" in spec) |
|
532 |
apply auto |
|
533 |
done |
|
534 |
||
535 |
lemma max_Suc_number_of [simp]: |
|
536 |
"max (number_of v) (Suc n) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
537 |
(let pv = number_of (Int.pred v) in |
23164 | 538 |
if neg pv then Suc n else Suc(max (nat pv) n))" |
539 |
apply (simp only: Let_def neg_eq_less_0 number_of_pred nat_number_of_def |
|
540 |
split add: split_if nat.split) |
|
541 |
apply (rule_tac x = "number_of v" in spec) |
|
542 |
apply auto |
|
543 |
done |
|
544 |
||
545 |
lemma min_number_of_Suc [simp]: |
|
546 |
"min (Suc n) (number_of v) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
547 |
(let pv = number_of (Int.pred v) in |
23164 | 548 |
if neg pv then 0 else Suc(min n (nat pv)))" |
549 |
apply (simp only: Let_def neg_eq_less_0 number_of_pred nat_number_of_def |
|
550 |
split add: split_if nat.split) |
|
551 |
apply (rule_tac x = "number_of v" in spec) |
|
552 |
apply auto |
|
553 |
done |
|
554 |
||
555 |
lemma min_Suc_number_of [simp]: |
|
556 |
"min (number_of v) (Suc n) = |
|
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
557 |
(let pv = number_of (Int.pred v) in |
23164 | 558 |
if neg pv then 0 else Suc(min (nat pv) n))" |
559 |
apply (simp only: Let_def neg_eq_less_0 number_of_pred nat_number_of_def |
|
560 |
split add: split_if nat.split) |
|
561 |
apply (rule_tac x = "number_of v" in spec) |
|
562 |
apply auto |
|
563 |
done |
|
564 |
||
565 |
subsection{*Literal arithmetic involving powers*} |
|
566 |
||
567 |
lemma nat_power_eq: "(0::int) <= z ==> nat (z^n) = nat z ^ n" |
|
568 |
apply (induct "n") |
|
569 |
apply (simp_all (no_asm_simp) add: nat_mult_distrib) |
|
570 |
done |
|
571 |
||
572 |
lemma power_nat_number_of: |
|
573 |
"(number_of v :: nat) ^ n = |
|
574 |
(if neg (number_of v :: int) then 0^n else nat ((number_of v :: int) ^ n))" |
|
575 |
by (simp only: simp_thms neg_nat not_neg_eq_ge_0 nat_number_of_def nat_power_eq |
|
576 |
split add: split_if cong: imp_cong) |
|
577 |
||
578 |
||
579 |
lemmas power_nat_number_of_number_of = power_nat_number_of [of _ "number_of w", standard] |
|
580 |
declare power_nat_number_of_number_of [simp] |
|
581 |
||
582 |
||
583 |
||
23294 | 584 |
text{*For arbitrary rings*} |
23164 | 585 |
|
23294 | 586 |
lemma power_number_of_even: |
587 |
fixes z :: "'a::{number_ring,recpower}" |
|
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
588 |
shows "z ^ number_of (Int.Bit0 w) = (let w = z ^ (number_of w) in w * w)" |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
589 |
unfolding Let_def nat_number_of_def number_of_Bit0 |
23164 | 590 |
apply (rule_tac x = "number_of w" in spec, clarify) |
591 |
apply (case_tac " (0::int) <= x") |
|
592 |
apply (auto simp add: nat_mult_distrib power_even_eq power2_eq_square) |
|
593 |
done |
|
594 |
||
23294 | 595 |
lemma power_number_of_odd: |
596 |
fixes z :: "'a::{number_ring,recpower}" |
|
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
597 |
shows "z ^ number_of (Int.Bit1 w) = (if (0::int) <= number_of w |
23164 | 598 |
then (let w = z ^ (number_of w) in z * w * w) else 1)" |
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
599 |
unfolding Let_def nat_number_of_def number_of_Bit1 |
23164 | 600 |
apply (rule_tac x = "number_of w" in spec, auto) |
601 |
apply (simp only: nat_add_distrib nat_mult_distrib) |
|
602 |
apply simp |
|
23294 | 603 |
apply (auto simp add: nat_add_distrib nat_mult_distrib power_even_eq power2_eq_square neg_nat power_Suc) |
23164 | 604 |
done |
605 |
||
23294 | 606 |
lemmas zpower_number_of_even = power_number_of_even [where 'a=int] |
607 |
lemmas zpower_number_of_odd = power_number_of_odd [where 'a=int] |
|
23164 | 608 |
|
23294 | 609 |
lemmas power_number_of_even_number_of [simp] = |
610 |
power_number_of_even [of "number_of v", standard] |
|
23164 | 611 |
|
23294 | 612 |
lemmas power_number_of_odd_number_of [simp] = |
613 |
power_number_of_odd [of "number_of v", standard] |
|
23164 | 614 |
|
615 |
||
616 |
||
617 |
ML |
|
618 |
{* |
|
26342 | 619 |
val numeral_ss = @{simpset} addsimps @{thms numerals}; |
23164 | 620 |
|
621 |
val nat_bin_arith_setup = |
|
24093 | 622 |
LinArith.map_data |
23164 | 623 |
(fn {add_mono_thms, mult_mono_thms, inj_thms, lessD, neqE, simpset} => |
624 |
{add_mono_thms = add_mono_thms, mult_mono_thms = mult_mono_thms, |
|
625 |
inj_thms = inj_thms, |
|
626 |
lessD = lessD, neqE = neqE, |
|
627 |
simpset = simpset addsimps [Suc_nat_number_of, int_nat_number_of, |
|
25481 | 628 |
@{thm not_neg_number_of_Pls}, @{thm neg_number_of_Min}, |
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
629 |
@{thm neg_number_of_Bit0}, @{thm neg_number_of_Bit1}]}) |
23164 | 630 |
*} |
631 |
||
24075 | 632 |
declaration {* K nat_bin_arith_setup *} |
23164 | 633 |
|
634 |
(* Enable arith to deal with div/mod k where k is a numeral: *) |
|
635 |
declare split_div[of _ _ "number_of k", standard, arith_split] |
|
636 |
declare split_mod[of _ _ "number_of k", standard, arith_split] |
|
637 |
||
638 |
lemma nat_number_of_Pls: "Numeral0 = (0::nat)" |
|
639 |
by (simp add: number_of_Pls nat_number_of_def) |
|
640 |
||
25919
8b1c0d434824
joined theories IntDef, Numeral, IntArith to theory Int
haftmann
parents:
25571
diff
changeset
|
641 |
lemma nat_number_of_Min: "number_of Int.Min = (0::nat)" |
23164 | 642 |
apply (simp only: number_of_Min nat_number_of_def nat_zminus_int) |
643 |
done |
|
644 |
||
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
645 |
lemma nat_number_of_Bit0: |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
646 |
"number_of (Int.Bit0 w) = (let n::nat = number_of w in n + n)" |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
647 |
apply (simp only: nat_number_of_def Let_def) |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
648 |
apply (cases "neg (number_of w :: int)") |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
649 |
apply (simp add: neg_nat neg_number_of_Bit0) |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
650 |
apply (rule int_int_eq [THEN iffD1]) |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
651 |
apply (simp only: not_neg_nat neg_number_of_Bit0 int_Suc zadd_int [symmetric] simp_thms) |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
652 |
apply (simp only: number_of_Bit0 zadd_assoc) |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
653 |
apply simp |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
654 |
done |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
655 |
|
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
656 |
lemma nat_number_of_Bit1: |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
657 |
"number_of (Int.Bit1 w) = |
23164 | 658 |
(if neg (number_of w :: int) then 0 |
659 |
else let n = number_of w in Suc (n + n))" |
|
660 |
apply (simp only: nat_number_of_def Let_def split: split_if) |
|
661 |
apply (intro conjI impI) |
|
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
662 |
apply (simp add: neg_nat neg_number_of_Bit1) |
23164 | 663 |
apply (rule int_int_eq [THEN iffD1]) |
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
664 |
apply (simp only: not_neg_nat neg_number_of_Bit1 int_Suc zadd_int [symmetric] simp_thms) |
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
665 |
apply (simp only: number_of_Bit1 zadd_assoc) |
23164 | 666 |
done |
667 |
||
668 |
lemmas nat_number = |
|
669 |
nat_number_of_Pls nat_number_of_Min |
|
26086
3c243098b64a
New simpler representation of numerals, using Bit0 and Bit1 instead of BIT, B0, and B1
huffman
parents:
25965
diff
changeset
|
670 |
nat_number_of_Bit0 nat_number_of_Bit1 |
23164 | 671 |
|
672 |
lemma Let_Suc [simp]: "Let (Suc n) f == f (Suc n)" |
|
673 |
by (simp add: Let_def) |
|
674 |
||
675 |
lemma power_m1_even: "(-1) ^ (2*n) = (1::'a::{number_ring,recpower})" |
|
23294 | 676 |
by (simp add: power_mult power_Suc); |
23164 | 677 |
|
678 |
lemma power_m1_odd: "(-1) ^ Suc(2*n) = (-1::'a::{number_ring,recpower})" |
|
679 |
by (simp add: power_mult power_Suc); |
|
680 |
||
681 |
||
682 |
subsection{*Literal arithmetic and @{term of_nat}*} |
|
683 |
||
684 |
lemma of_nat_double: |
|
685 |
"0 \<le> x ==> of_nat (nat (2 * x)) = of_nat (nat x) + of_nat (nat x)" |
|
686 |
by (simp only: mult_2 nat_add_distrib of_nat_add) |
|
687 |
||
688 |
lemma nat_numeral_m1_eq_0: "-1 = (0::nat)" |
|
689 |
by (simp only: nat_number_of_def) |
|
690 |
||
691 |
lemma of_nat_number_of_lemma: |
|
692 |
"of_nat (number_of v :: nat) = |
|
693 |
(if 0 \<le> (number_of v :: int) |
|
694 |
then (number_of v :: 'a :: number_ring) |
|
695 |
else 0)" |
|
696 |
by (simp add: int_number_of_def nat_number_of_def number_of_eq of_nat_nat); |
|
697 |
||
698 |
lemma of_nat_number_of_eq [simp]: |
|
699 |
"of_nat (number_of v :: nat) = |
|
700 |
(if neg (number_of v :: int) then 0 |
|
701 |
else (number_of v :: 'a :: number_ring))" |
|
702 |
by (simp only: of_nat_number_of_lemma neg_def, simp) |
|
703 |
||
704 |
||
705 |
subsection {*Lemmas for the Combination and Cancellation Simprocs*} |
|
706 |
||
707 |
lemma nat_number_of_add_left: |
|
708 |
"number_of v + (number_of v' + (k::nat)) = |
|
709 |
(if neg (number_of v :: int) then number_of v' + k |
|
710 |
else if neg (number_of v' :: int) then number_of v + k |
|
711 |
else number_of (v + v') + k)" |
|
712 |
by simp |
|
713 |
||
714 |
lemma nat_number_of_mult_left: |
|
715 |
"number_of v * (number_of v' * (k::nat)) = |
|
716 |
(if neg (number_of v :: int) then 0 |
|
717 |
else number_of (v * v') * k)" |
|
718 |
by simp |
|
719 |
||
720 |
||
721 |
subsubsection{*For @{text combine_numerals}*} |
|
722 |
||
723 |
lemma left_add_mult_distrib: "i*u + (j*u + k) = (i+j)*u + (k::nat)" |
|
724 |
by (simp add: add_mult_distrib) |
|
725 |
||
726 |
||
727 |
subsubsection{*For @{text cancel_numerals}*} |
|
728 |
||
729 |
lemma nat_diff_add_eq1: |
|
730 |
"j <= (i::nat) ==> ((i*u + m) - (j*u + n)) = (((i-j)*u + m) - n)" |
|
731 |
by (simp split add: nat_diff_split add: add_mult_distrib) |
|
732 |
||
733 |
lemma nat_diff_add_eq2: |
|
734 |
"i <= (j::nat) ==> ((i*u + m) - (j*u + n)) = (m - ((j-i)*u + n))" |
|
735 |
by (simp split add: nat_diff_split add: add_mult_distrib) |
|
736 |
||
737 |
lemma nat_eq_add_iff1: |
|
738 |
"j <= (i::nat) ==> (i*u + m = j*u + n) = ((i-j)*u + m = n)" |
|
739 |
by (auto split add: nat_diff_split simp add: add_mult_distrib) |
|
740 |
||
741 |
lemma nat_eq_add_iff2: |
|
742 |
"i <= (j::nat) ==> (i*u + m = j*u + n) = (m = (j-i)*u + n)" |
|
743 |
by (auto split add: nat_diff_split simp add: add_mult_distrib) |
|
744 |
||
745 |
lemma nat_less_add_iff1: |
|
746 |
"j <= (i::nat) ==> (i*u + m < j*u + n) = ((i-j)*u + m < n)" |
|
747 |
by (auto split add: nat_diff_split simp add: add_mult_distrib) |
|
748 |
||
749 |
lemma nat_less_add_iff2: |
|
750 |
"i <= (j::nat) ==> (i*u + m < j*u + n) = (m < (j-i)*u + n)" |
|
751 |
by (auto split add: nat_diff_split simp add: add_mult_distrib) |
|
752 |
||
753 |
lemma nat_le_add_iff1: |
|
754 |
"j <= (i::nat) ==> (i*u + m <= j*u + n) = ((i-j)*u + m <= n)" |
|
755 |
by (auto split add: nat_diff_split simp add: add_mult_distrib) |
|
756 |
||
757 |
lemma nat_le_add_iff2: |
|
758 |
"i <= (j::nat) ==> (i*u + m <= j*u + n) = (m <= (j-i)*u + n)" |
|
759 |
by (auto split add: nat_diff_split simp add: add_mult_distrib) |
|
760 |
||
761 |
||
762 |
subsubsection{*For @{text cancel_numeral_factors} *} |
|
763 |
||
764 |
lemma nat_mult_le_cancel1: "(0::nat) < k ==> (k*m <= k*n) = (m<=n)" |
|
765 |
by auto |
|
766 |
||
767 |
lemma nat_mult_less_cancel1: "(0::nat) < k ==> (k*m < k*n) = (m<n)" |
|
768 |
by auto |
|
769 |
||
770 |
lemma nat_mult_eq_cancel1: "(0::nat) < k ==> (k*m = k*n) = (m=n)" |
|
771 |
by auto |
|
772 |
||
773 |
lemma nat_mult_div_cancel1: "(0::nat) < k ==> (k*m) div (k*n) = (m div n)" |
|
774 |
by auto |
|
775 |
||
23969 | 776 |
lemma nat_mult_dvd_cancel_disj[simp]: |
777 |
"(k*m) dvd (k*n) = (k=0 | m dvd (n::nat))" |
|
778 |
by(auto simp: dvd_eq_mod_eq_0 mod_mult_distrib2[symmetric]) |
|
779 |
||
780 |
lemma nat_mult_dvd_cancel1: "0 < k \<Longrightarrow> (k*m) dvd (k*n::nat) = (m dvd n)" |
|
781 |
by(auto) |
|
782 |
||
23164 | 783 |
|
784 |
subsubsection{*For @{text cancel_factor} *} |
|
785 |
||
786 |
lemma nat_mult_le_cancel_disj: "(k*m <= k*n) = ((0::nat) < k --> m<=n)" |
|
787 |
by auto |
|
788 |
||
789 |
lemma nat_mult_less_cancel_disj: "(k*m < k*n) = ((0::nat) < k & m<n)" |
|
790 |
by auto |
|
791 |
||
792 |
lemma nat_mult_eq_cancel_disj: "(k*m = k*n) = (k = (0::nat) | m=n)" |
|
793 |
by auto |
|
794 |
||
23969 | 795 |
lemma nat_mult_div_cancel_disj[simp]: |
23164 | 796 |
"(k*m) div (k*n) = (if k = (0::nat) then 0 else m div n)" |
797 |
by (simp add: nat_mult_div_cancel1) |
|
798 |
||
799 |
end |