author | paulson |
Fri, 26 Sep 1997 10:21:14 +0200 | |
changeset 3718 | d78cf498a88c |
parent 3496 | 32e7edc609fd |
child 3724 | f33e301a89f5 |
permissions | -rw-r--r-- |
3366 | 1 |
(* Title: HOL/Divides.ML |
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ID: $Id$ |
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Author: Lawrence C Paulson, Cambridge University Computer Laboratory |
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Copyright 1993 University of Cambridge |
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The division operators div, mod and the divides relation "dvd" |
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*) |
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(** Less-then properties **) |
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(*In ordinary notation: if 0<n and n<=m then m-n < m *) |
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goal Arith.thy "!!m. [| 0<n; ~ m<n |] ==> m - n < m"; |
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by (subgoal_tac "0<n --> ~ m<n --> m - n < m" 1); |
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by (Blast_tac 1); |
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by (res_inst_tac [("m","m"),("n","n")] diff_induct 1); |
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by (ALLGOALS(asm_simp_tac(!simpset addsimps [diff_less_Suc]))); |
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qed "diff_less"; |
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val wf_less_trans = [eq_reflection, wf_pred_nat RS wf_trancl] MRS |
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def_wfrec RS trans; |
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||
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(*** Remainder ***) |
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goal thy "(%m. m mod n) = wfrec (trancl pred_nat) \ |
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\ (%f j. if j<n then j else f (j-n))"; |
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by (simp_tac (!simpset addsimps [mod_def]) 1); |
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qed "mod_eq"; |
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goal thy "!!m. m<n ==> m mod n = m"; |
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by (rtac (mod_eq RS wf_less_trans) 1); |
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by (Asm_simp_tac 1); |
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qed "mod_less"; |
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||
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goal thy "!!m. [| 0<n; ~m<n |] ==> m mod n = (m-n) mod n"; |
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by (rtac (mod_eq RS wf_less_trans) 1); |
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by (asm_simp_tac (!simpset addsimps [diff_less, cut_apply, less_eq]) 1); |
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qed "mod_geq"; |
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||
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goal thy "m mod 1 = 0"; |
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by (induct_tac "m" 1); |
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by (ALLGOALS (asm_simp_tac (!simpset addsimps [mod_less, mod_geq]))); |
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qed "mod_1"; |
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Addsimps [mod_1]; |
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||
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goal thy "!!n. 0<n ==> n mod n = 0"; |
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by (asm_simp_tac (!simpset addsimps [mod_less, mod_geq]) 1); |
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qed "mod_self"; |
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||
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goal thy "!!n. 0<n ==> (m+n) mod n = m mod n"; |
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by (subgoal_tac "(n + m) mod n = (n+m-n) mod n" 1); |
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by (stac (mod_geq RS sym) 2); |
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by (ALLGOALS (asm_full_simp_tac (!simpset addsimps [add_commute]))); |
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qed "mod_eq_add"; |
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||
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goal thy "!!k. [| 0<k; 0<n |] ==> (m mod n)*k = (m*k) mod (n*k)"; |
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by (res_inst_tac [("n","m")] less_induct 1); |
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by (case_tac "na<n" 1); |
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(*case na<n*) |
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by (asm_simp_tac (!simpset addsimps [mod_less]) 1); |
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(*case n<=na*) |
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by (asm_simp_tac (!simpset addsimps [mod_geq, diff_less, zero_less_mult_iff, |
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diff_mult_distrib]) 1); |
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qed "mod_mult_distrib"; |
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goal thy "!!k. [| 0<k; 0<n |] ==> k*(m mod n) = (k*m) mod (k*n)"; |
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by (res_inst_tac [("n","m")] less_induct 1); |
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by (case_tac "na<n" 1); |
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(*case na<n*) |
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by (asm_simp_tac (!simpset addsimps [mod_less]) 1); |
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(*case n<=na*) |
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by (asm_simp_tac (!simpset addsimps [mod_geq, diff_less, zero_less_mult_iff, |
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diff_mult_distrib2]) 1); |
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qed "mod_mult_distrib2"; |
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||
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goal thy "!!n. 0<n ==> m*n mod n = 0"; |
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by (induct_tac "m" 1); |
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by (asm_simp_tac (!simpset addsimps [mod_less]) 1); |
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by (dres_inst_tac [("m","m*n")] mod_eq_add 1); |
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by (asm_full_simp_tac (!simpset addsimps [add_commute]) 1); |
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qed "mod_mult_self_is_0"; |
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Addsimps [mod_mult_self_is_0]; |
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(*** Quotient ***) |
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goal thy "(%m. m div n) = wfrec (trancl pred_nat) \ |
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\ (%f j. if j<n then 0 else Suc (f (j-n)))"; |
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by (simp_tac (!simpset addsimps [div_def]) 1); |
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qed "div_eq"; |
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goal thy "!!m. m<n ==> m div n = 0"; |
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by (rtac (div_eq RS wf_less_trans) 1); |
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by (Asm_simp_tac 1); |
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qed "div_less"; |
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goal thy "!!M. [| 0<n; ~m<n |] ==> m div n = Suc((m-n) div n)"; |
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by (rtac (div_eq RS wf_less_trans) 1); |
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by (asm_simp_tac (!simpset addsimps [diff_less, cut_apply, less_eq]) 1); |
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qed "div_geq"; |
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(*Main Result about quotient and remainder.*) |
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goal thy "!!m. 0<n ==> (m div n)*n + m mod n = m"; |
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by (res_inst_tac [("n","m")] less_induct 1); |
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by (rename_tac "k" 1); (*Variable name used in line below*) |
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by (case_tac "k<n" 1); |
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by (ALLGOALS (asm_simp_tac(!simpset addsimps ([add_assoc] @ |
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[mod_less, mod_geq, div_less, div_geq, |
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add_diff_inverse, diff_less])))); |
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qed "mod_div_equality"; |
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goal thy "m div 1 = m"; |
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by (induct_tac "m" 1); |
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by (ALLGOALS (asm_simp_tac (!simpset addsimps [div_less, div_geq]))); |
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qed "div_1"; |
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Addsimps [div_1]; |
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goal thy "!!n. 0<n ==> n div n = 1"; |
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by (asm_simp_tac (!simpset addsimps [div_less, div_geq]) 1); |
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qed "div_self"; |
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||
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1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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121 |
(* Monotonicity of div in first argument *) |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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goal thy "!!n. 0<k ==> ALL m. m <= n --> (m div k) <= (n div k)"; |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
123 |
by (res_inst_tac [("n","n")] less_induct 1); |
3718 | 124 |
by (Clarify_tac 1); |
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
125 |
by (case_tac "na<k" 1); |
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Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
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(* 1 case n<k *) |
1e93eb09ebb9
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nipkow
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|
127 |
by (subgoal_tac "m<k" 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
128 |
by (asm_simp_tac (!simpset addsimps [div_less]) 1); |
3496 | 129 |
by (trans_tac 1); |
3484
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Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
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(* 2 case n >= k *) |
1e93eb09ebb9
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parents:
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|
131 |
by (case_tac "m<k" 1); |
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parents:
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|
132 |
(* 2.1 case m<k *) |
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|
133 |
by (asm_simp_tac (!simpset addsimps [div_less]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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(* 2.2 case m>=k *) |
3496 | 135 |
by (asm_simp_tac (!simpset addsimps [div_geq, diff_less, diff_le_mono]) 1); |
3484
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Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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qed_spec_mp "div_le_mono"; |
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nipkow
parents:
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137 |
|
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
138 |
|
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
139 |
(* Antimonotonicity of div in second argument *) |
1e93eb09ebb9
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goal thy "!!k m n. [| 0<m; m<=n |] ==> (k div n) <= (k div m)"; |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
141 |
by (subgoal_tac "0<n" 1); |
3496 | 142 |
by (trans_tac 2); |
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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changeset
|
143 |
by (res_inst_tac [("n","k")] less_induct 1); |
3496 | 144 |
by (Simp_tac 1); |
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by (rename_tac "k" 1); |
|
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
146 |
by (case_tac "k<n" 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
147 |
by (asm_simp_tac (!simpset addsimps [div_less]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
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changeset
|
148 |
by (subgoal_tac "~(k<m)" 1); |
3496 | 149 |
by (trans_tac 2); |
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
150 |
by (asm_simp_tac (!simpset addsimps [div_geq]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
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changeset
|
151 |
by (subgoal_tac "(k-n) div n <= (k-m) div n" 1); |
3496 | 152 |
by (best_tac (!claset addIs [le_trans] |
153 |
addss (!simpset addsimps [diff_less])) 1); |
|
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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changeset
|
154 |
by (REPEAT (eresolve_tac [div_le_mono,diff_le_mono2] 1)); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
155 |
qed "div_le_mono2"; |
1e93eb09ebb9
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nipkow
parents:
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|
156 |
|
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
157 |
goal thy "!!m n. 0<n ==> m div n <= m"; |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
158 |
by (subgoal_tac "m div n <= m div 1" 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
159 |
by (Asm_full_simp_tac 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
160 |
by (rtac div_le_mono2 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
161 |
by (ALLGOALS trans_tac); |
1e93eb09ebb9
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nipkow
parents:
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162 |
qed "div_le_dividend"; |
1e93eb09ebb9
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nipkow
parents:
3457
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|
163 |
Addsimps [div_le_dividend]; |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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changeset
|
164 |
|
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
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|
165 |
(* Similar for "less than" *) |
1e93eb09ebb9
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nipkow
parents:
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|
166 |
goal thy "!!m n. 1<n ==> (0 < m) --> (m div n < m)"; |
1e93eb09ebb9
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nipkow
parents:
3457
diff
changeset
|
167 |
by (res_inst_tac [("n","m")] less_induct 1); |
3496 | 168 |
by (Simp_tac 1); |
169 |
by (rename_tac "m" 1); |
|
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
170 |
by (case_tac "m<n" 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
171 |
by (asm_full_simp_tac (!simpset addsimps [div_less]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
172 |
by (subgoal_tac "0<n" 1); |
3496 | 173 |
by (trans_tac 2); |
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
174 |
by (asm_full_simp_tac (!simpset addsimps [div_geq]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
175 |
by (case_tac "n<m" 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
176 |
by (subgoal_tac "(m-n) div n < (m-n)" 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
177 |
by (REPEAT (ares_tac [impI,less_trans_Suc] 1)); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
178 |
by (asm_full_simp_tac (!simpset addsimps [diff_less]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
179 |
by (dres_inst_tac [("m","n")] less_imp_diff_positive 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
180 |
by (asm_full_simp_tac (!simpset addsimps [diff_less]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
181 |
(* case n=m *) |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
182 |
by (subgoal_tac "m=n" 1); |
3496 | 183 |
by (trans_tac 2); |
3484
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
184 |
by (asm_simp_tac (!simpset addsimps [div_less]) 1); |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
185 |
qed_spec_mp "div_less_dividend"; |
1e93eb09ebb9
Added the following lemmas tp Divides and a few others to Arith and NatDef:
nipkow
parents:
3457
diff
changeset
|
186 |
Addsimps [div_less_dividend]; |
3366 | 187 |
|
188 |
(*** Further facts about mod (mainly for the mutilated chess board ***) |
|
189 |
||
190 |
goal thy |
|
191 |
"!!m n. 0<n ==> \ |
|
192 |
\ Suc(m) mod n = (if Suc(m mod n) = n then 0 else Suc(m mod n))"; |
|
193 |
by (res_inst_tac [("n","m")] less_induct 1); |
|
194 |
by (excluded_middle_tac "Suc(na)<n" 1); |
|
195 |
(* case Suc(na) < n *) |
|
196 |
by (forward_tac [lessI RS less_trans] 2); |
|
197 |
by (asm_simp_tac (!simpset addsimps [mod_less, less_not_refl2 RS not_sym]) 2); |
|
198 |
(* case n <= Suc(na) *) |
|
199 |
by (asm_full_simp_tac (!simpset addsimps [not_less_iff_le, mod_geq]) 1); |
|
200 |
by (etac (le_imp_less_or_eq RS disjE) 1); |
|
201 |
by (asm_simp_tac (!simpset addsimps [Suc_diff_n]) 1); |
|
202 |
by (asm_full_simp_tac (!simpset addsimps [not_less_eq RS sym, |
|
203 |
diff_less, mod_geq]) 1); |
|
204 |
by (asm_simp_tac (!simpset addsimps [mod_less]) 1); |
|
205 |
qed "mod_Suc"; |
|
206 |
||
207 |
goal thy "!!m n. 0<n ==> m mod n < n"; |
|
208 |
by (res_inst_tac [("n","m")] less_induct 1); |
|
209 |
by (excluded_middle_tac "na<n" 1); |
|
210 |
(*case na<n*) |
|
211 |
by (asm_simp_tac (!simpset addsimps [mod_less]) 2); |
|
212 |
(*case n le na*) |
|
213 |
by (asm_full_simp_tac (!simpset addsimps [mod_geq, diff_less]) 1); |
|
214 |
qed "mod_less_divisor"; |
|
215 |
||
216 |
||
217 |
(** Evens and Odds **) |
|
218 |
||
219 |
(*With less_zeroE, causes case analysis on b<2*) |
|
220 |
AddSEs [less_SucE]; |
|
221 |
||
222 |
goal thy "!!k b. b<2 ==> k mod 2 = b | k mod 2 = (if b=1 then 0 else 1)"; |
|
223 |
by (subgoal_tac "k mod 2 < 2" 1); |
|
224 |
by (asm_simp_tac (!simpset addsimps [mod_less_divisor]) 2); |
|
225 |
by (asm_simp_tac (!simpset setloop split_tac [expand_if]) 1); |
|
226 |
by (Blast_tac 1); |
|
227 |
qed "mod2_cases"; |
|
228 |
||
229 |
goal thy "Suc(Suc(m)) mod 2 = m mod 2"; |
|
230 |
by (subgoal_tac "m mod 2 < 2" 1); |
|
231 |
by (asm_simp_tac (!simpset addsimps [mod_less_divisor]) 2); |
|
232 |
by (Step_tac 1); |
|
233 |
by (ALLGOALS (asm_simp_tac (!simpset addsimps [mod_Suc]))); |
|
234 |
qed "mod2_Suc_Suc"; |
|
235 |
Addsimps [mod2_Suc_Suc]; |
|
236 |
||
237 |
goal thy "!!m. m mod 2 ~= 0 ==> m mod 2 = 1"; |
|
238 |
by (subgoal_tac "m mod 2 < 2" 1); |
|
239 |
by (asm_simp_tac (!simpset addsimps [mod_less_divisor]) 2); |
|
240 |
by (safe_tac (!claset addSEs [lessE])); |
|
241 |
by (ALLGOALS (blast_tac (!claset addIs [sym]))); |
|
242 |
qed "mod2_neq_0"; |
|
243 |
||
244 |
goal thy "(m+m) mod 2 = 0"; |
|
245 |
by (induct_tac "m" 1); |
|
246 |
by (simp_tac (!simpset addsimps [mod_less]) 1); |
|
3427
e7cef2081106
Removed a few redundant additions of simprules or classical rules
paulson
parents:
3366
diff
changeset
|
247 |
by (Asm_simp_tac 1); |
3366 | 248 |
qed "mod2_add_self"; |
249 |
Addsimps [mod2_add_self]; |
|
250 |
||
251 |
Delrules [less_SucE]; |
|
252 |
||
253 |
||
254 |
(*** More division laws ***) |
|
255 |
||
256 |
goal thy "!!n. 0<n ==> m*n div n = m"; |
|
257 |
by (cut_inst_tac [("m", "m*n")] mod_div_equality 1); |
|
3457 | 258 |
by (assume_tac 1); |
3366 | 259 |
by (asm_full_simp_tac (!simpset addsimps [mod_mult_self_is_0]) 1); |
260 |
qed "div_mult_self_is_m"; |
|
261 |
Addsimps [div_mult_self_is_m]; |
|
262 |
||
263 |
(*Cancellation law for division*) |
|
264 |
goal thy "!!k. [| 0<n; 0<k |] ==> (k*m) div (k*n) = m div n"; |
|
265 |
by (res_inst_tac [("n","m")] less_induct 1); |
|
266 |
by (case_tac "na<n" 1); |
|
267 |
by (asm_simp_tac (!simpset addsimps [div_less, zero_less_mult_iff, |
|
268 |
mult_less_mono2]) 1); |
|
269 |
by (subgoal_tac "~ k*na < k*n" 1); |
|
270 |
by (asm_simp_tac |
|
271 |
(!simpset addsimps [zero_less_mult_iff, div_geq, |
|
272 |
diff_mult_distrib2 RS sym, diff_less]) 1); |
|
273 |
by (asm_full_simp_tac (!simpset addsimps [not_less_iff_le, |
|
274 |
le_refl RS mult_le_mono]) 1); |
|
275 |
qed "div_cancel"; |
|
276 |
Addsimps [div_cancel]; |
|
277 |
||
278 |
goal thy "!!k. [| 0<n; 0<k |] ==> (k*m) mod (k*n) = k * (m mod n)"; |
|
279 |
by (res_inst_tac [("n","m")] less_induct 1); |
|
280 |
by (case_tac "na<n" 1); |
|
281 |
by (asm_simp_tac (!simpset addsimps [mod_less, zero_less_mult_iff, |
|
282 |
mult_less_mono2]) 1); |
|
283 |
by (subgoal_tac "~ k*na < k*n" 1); |
|
284 |
by (asm_simp_tac |
|
285 |
(!simpset addsimps [zero_less_mult_iff, mod_geq, |
|
286 |
diff_mult_distrib2 RS sym, diff_less]) 1); |
|
287 |
by (asm_full_simp_tac (!simpset addsimps [not_less_iff_le, |
|
288 |
le_refl RS mult_le_mono]) 1); |
|
289 |
qed "mult_mod_distrib"; |
|
290 |
||
291 |
||
292 |
(************************************************) |
|
293 |
(** Divides Relation **) |
|
294 |
(************************************************) |
|
295 |
||
296 |
goalw thy [dvd_def] "m dvd 0"; |
|
297 |
by (fast_tac (!claset addIs [mult_0_right RS sym]) 1); |
|
298 |
qed "dvd_0_right"; |
|
299 |
Addsimps [dvd_0_right]; |
|
300 |
||
301 |
goalw thy [dvd_def] "!!m. 0 dvd m ==> m = 0"; |
|
302 |
by (fast_tac (!claset addss !simpset) 1); |
|
303 |
qed "dvd_0_left"; |
|
304 |
||
305 |
goalw thy [dvd_def] "1 dvd k"; |
|
306 |
by (Simp_tac 1); |
|
307 |
qed "dvd_1_left"; |
|
308 |
AddIffs [dvd_1_left]; |
|
309 |
||
310 |
goalw thy [dvd_def] "m dvd m"; |
|
311 |
by (fast_tac (!claset addIs [mult_1_right RS sym]) 1); |
|
312 |
qed "dvd_refl"; |
|
313 |
Addsimps [dvd_refl]; |
|
314 |
||
315 |
goalw thy [dvd_def] "!!m n p. [| m dvd n; n dvd p |] ==> m dvd p"; |
|
316 |
by (fast_tac (!claset addIs [mult_assoc] ) 1); |
|
317 |
qed "dvd_trans"; |
|
318 |
||
319 |
goalw thy [dvd_def] "!!m n. [| m dvd n; n dvd m |] ==> m=n"; |
|
320 |
by (fast_tac (!claset addDs [mult_eq_self_implies_10] |
|
321 |
addss (!simpset addsimps [mult_assoc, mult_eq_1_iff])) 1); |
|
322 |
qed "dvd_anti_sym"; |
|
323 |
||
324 |
goalw thy [dvd_def] "!!k. [| k dvd m; k dvd n |] ==> k dvd (m + n)"; |
|
325 |
by (blast_tac (!claset addIs [add_mult_distrib2 RS sym]) 1); |
|
326 |
qed "dvd_add"; |
|
327 |
||
328 |
goalw thy [dvd_def] "!!k. [| k dvd m; k dvd n |] ==> k dvd (m-n)"; |
|
329 |
by (blast_tac (!claset addIs [diff_mult_distrib2 RS sym]) 1); |
|
330 |
qed "dvd_diff"; |
|
331 |
||
332 |
goal thy "!!k. [| k dvd (m-n); k dvd n; n<=m |] ==> k dvd m"; |
|
3457 | 333 |
by (etac (not_less_iff_le RS iffD2 RS add_diff_inverse RS subst) 1); |
3366 | 334 |
by (blast_tac (!claset addIs [dvd_add]) 1); |
335 |
qed "dvd_diffD"; |
|
336 |
||
337 |
goalw thy [dvd_def] "!!k. k dvd n ==> k dvd (m*n)"; |
|
338 |
by (blast_tac (!claset addIs [mult_left_commute]) 1); |
|
339 |
qed "dvd_mult"; |
|
340 |
||
341 |
goal thy "!!k. k dvd m ==> k dvd (m*n)"; |
|
342 |
by (stac mult_commute 1); |
|
343 |
by (etac dvd_mult 1); |
|
344 |
qed "dvd_mult2"; |
|
345 |
||
346 |
(* k dvd (m*k) *) |
|
347 |
AddIffs [dvd_refl RS dvd_mult, dvd_refl RS dvd_mult2]; |
|
348 |
||
349 |
goalw thy [dvd_def] "!!m. [| f dvd m; f dvd n; 0<n |] ==> f dvd (m mod n)"; |
|
3718 | 350 |
by (Clarify_tac 1); |
3366 | 351 |
by (full_simp_tac (!simpset addsimps [zero_less_mult_iff]) 1); |
352 |
by (res_inst_tac |
|
353 |
[("x", "(((k div ka)*ka + k mod ka) - ((f*k) div (f*ka)) * ka)")] |
|
354 |
exI 1); |
|
355 |
by (asm_simp_tac (!simpset addsimps [diff_mult_distrib2, |
|
356 |
mult_mod_distrib, add_mult_distrib2]) 1); |
|
357 |
qed "dvd_mod"; |
|
358 |
||
359 |
goal thy "!!k. [| k dvd (m mod n); k dvd n; n~=0 |] ==> k dvd m"; |
|
360 |
by (subgoal_tac "k dvd ((m div n)*n + m mod n)" 1); |
|
361 |
by (asm_simp_tac (!simpset addsimps [dvd_add, dvd_mult]) 2); |
|
362 |
by (asm_full_simp_tac (!simpset addsimps [mod_div_equality, zero_less_eq]) 1); |
|
363 |
qed "dvd_mod_imp_dvd"; |
|
364 |
||
365 |
goalw thy [dvd_def] "!!k m n. [| (k*m) dvd (k*n); 0<k |] ==> m dvd n"; |
|
366 |
by (etac exE 1); |
|
367 |
by (asm_full_simp_tac (!simpset addsimps mult_ac) 1); |
|
368 |
by (Blast_tac 1); |
|
369 |
qed "dvd_mult_cancel"; |
|
370 |
||
371 |
goalw thy [dvd_def] "!!i j. [| i dvd m; j dvd n|] ==> (i*j) dvd (m*n)"; |
|
3718 | 372 |
by (Clarify_tac 1); |
3366 | 373 |
by (res_inst_tac [("x","k*ka")] exI 1); |
374 |
by (asm_simp_tac (!simpset addsimps mult_ac) 1); |
|
375 |
qed "mult_dvd_mono"; |
|
376 |
||
377 |
goalw thy [dvd_def] "!!c. (i*j) dvd k ==> i dvd k"; |
|
378 |
by (full_simp_tac (!simpset addsimps [mult_assoc]) 1); |
|
379 |
by (Blast_tac 1); |
|
380 |
qed "dvd_mult_left"; |
|
381 |
||
382 |
goalw thy [dvd_def] "!!n. [| k dvd n; 0 < n |] ==> k <= n"; |
|
3718 | 383 |
by (Clarify_tac 1); |
3366 | 384 |
by (ALLGOALS (full_simp_tac (!simpset addsimps [zero_less_mult_iff]))); |
3457 | 385 |
by (etac conjE 1); |
386 |
by (rtac le_trans 1); |
|
387 |
by (rtac (le_refl RS mult_le_mono) 2); |
|
3366 | 388 |
by (etac Suc_leI 2); |
389 |
by (Simp_tac 1); |
|
390 |
qed "dvd_imp_le"; |
|
391 |
||
392 |
goalw thy [dvd_def] "!!k. 0<k ==> (k dvd n) = (n mod k = 0)"; |
|
393 |
by (Step_tac 1); |
|
394 |
by (stac mult_commute 1); |
|
395 |
by (Asm_simp_tac 1); |
|
396 |
by (eres_inst_tac [("t","n")] (mod_div_equality RS subst) 1); |
|
397 |
by (asm_simp_tac (!simpset addsimps [mult_commute]) 1); |
|
398 |
by (Blast_tac 1); |
|
399 |
qed "dvd_eq_mod_eq_0"; |