diff -r f04b33ce250f -r a4dc62a46ee4 Trancl.ML --- a/Trancl.ML Tue Oct 24 14:59:17 1995 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,237 +0,0 @@ -(* Title: HOL/trancl - ID: $Id$ - Author: Lawrence C Paulson, Cambridge University Computer Laboratory - Copyright 1992 University of Cambridge - -For trancl.thy. Theorems about the transitive closure of a relation -*) - -open Trancl; - -(** Natural deduction for trans(r) **) - -val prems = goalw Trancl.thy [trans_def] - "(!! x y z. [| :r; :r |] ==> :r) ==> trans(r)"; -by (REPEAT (ares_tac (prems@[allI,impI]) 1)); -qed "transI"; - -val major::prems = goalw Trancl.thy [trans_def] - "[| trans(r); :r; :r |] ==> :r"; -by (cut_facts_tac [major] 1); -by (fast_tac (HOL_cs addIs prems) 1); -qed "transD"; - -(** Identity relation **) - -goalw Trancl.thy [id_def] " : id"; -by (rtac CollectI 1); -by (rtac exI 1); -by (rtac refl 1); -qed "idI"; - -val major::prems = goalw Trancl.thy [id_def] - "[| p: id; !!x.[| p = |] ==> P \ -\ |] ==> P"; -by (rtac (major RS CollectE) 1); -by (etac exE 1); -by (eresolve_tac prems 1); -qed "idE"; - -goalw Trancl.thy [id_def] ":id = (a=b)"; -by(fast_tac prod_cs 1); -qed "pair_in_id_conv"; - -(** Composition of two relations **) - -val prems = goalw Trancl.thy [comp_def] - "[| :s; :r |] ==> : r O s"; -by (fast_tac (set_cs addIs prems) 1); -qed "compI"; - -(*proof requires higher-level assumptions or a delaying of hyp_subst_tac*) -val prems = goalw Trancl.thy [comp_def] - "[| xz : r O s; \ -\ !!x y z. [| xz = ; :s; :r |] ==> P \ -\ |] ==> P"; -by (cut_facts_tac prems 1); -by (REPEAT (eresolve_tac [CollectE, exE, conjE] 1 ORELSE ares_tac prems 1)); -qed "compE"; - -val prems = goal Trancl.thy - "[| : r O s; \ -\ !!y. [| :s; :r |] ==> P \ -\ |] ==> P"; -by (rtac compE 1); -by (REPEAT (ares_tac prems 1 ORELSE eresolve_tac [Pair_inject,ssubst] 1)); -qed "compEpair"; - -val comp_cs = prod_cs addIs [compI, idI] addSEs [compE, idE]; - -goal Trancl.thy "!!r s. [| r'<=r; s'<=s |] ==> (r' O s') <= (r O s)"; -by (fast_tac comp_cs 1); -qed "comp_mono"; - -goal Trancl.thy - "!!r s. [| s <= Sigma(A,%x.B); r <= Sigma(B,%x.C) |] ==> \ -\ (r O s) <= Sigma(A,%x.C)"; -by (fast_tac comp_cs 1); -qed "comp_subset_Sigma"; - - -(** The relation rtrancl **) - -goal Trancl.thy "mono(%s. id Un (r O s))"; -by (rtac monoI 1); -by (REPEAT (ares_tac [monoI, subset_refl, comp_mono, Un_mono] 1)); -qed "rtrancl_fun_mono"; - -val rtrancl_unfold = rtrancl_fun_mono RS (rtrancl_def RS def_lfp_Tarski); - -(*Reflexivity of rtrancl*) -goal Trancl.thy " : r^*"; -by (stac rtrancl_unfold 1); -by (fast_tac comp_cs 1); -qed "rtrancl_refl"; - -(*Closure under composition with r*) -val prems = goal Trancl.thy - "[| : r^*; : r |] ==> : r^*"; -by (stac rtrancl_unfold 1); -by (fast_tac (comp_cs addIs prems) 1); -qed "rtrancl_into_rtrancl"; - -(*rtrancl of r contains r*) -val [prem] = goal Trancl.thy "[| : r |] ==> : r^*"; -by (rtac (rtrancl_refl RS rtrancl_into_rtrancl) 1); -by (rtac prem 1); -qed "r_into_rtrancl"; - -(*monotonicity of rtrancl*) -goalw Trancl.thy [rtrancl_def] "!!r s. r <= s ==> r^* <= s^*"; -by(REPEAT(ares_tac [lfp_mono,Un_mono,comp_mono,subset_refl] 1)); -qed "rtrancl_mono"; - -(** standard induction rule **) - -val major::prems = goal Trancl.thy - "[| : r^*; \ -\ !!x. P(); \ -\ !!x y z.[| P(); : r^*; : r |] ==> P() |] \ -\ ==> P()"; -by (rtac ([rtrancl_def, rtrancl_fun_mono, major] MRS def_induct) 1); -by (fast_tac (comp_cs addIs prems) 1); -qed "rtrancl_full_induct"; - -(*nice induction rule*) -val major::prems = goal Trancl.thy - "[| : r^*; \ -\ P(a); \ -\ !!y z.[| : r^*; : r; P(y) |] ==> P(z) |] \ -\ ==> P(b)"; -(*by induction on this formula*) -by (subgoal_tac "! y. = --> P(y)" 1); -(*now solve first subgoal: this formula is sufficient*) -by (fast_tac HOL_cs 1); -(*now do the induction*) -by (resolve_tac [major RS rtrancl_full_induct] 1); -by (fast_tac (comp_cs addIs prems) 1); -by (fast_tac (comp_cs addIs prems) 1); -qed "rtrancl_induct"; - -(*transitivity of transitive closure!! -- by induction.*) -goal Trancl.thy "trans(r^*)"; -by (rtac transI 1); -by (res_inst_tac [("b","z")] rtrancl_induct 1); -by (DEPTH_SOLVE (eresolve_tac [asm_rl, rtrancl_into_rtrancl] 1)); -qed "trans_rtrancl"; - -(*elimination of rtrancl -- by induction on a special formula*) -val major::prems = goal Trancl.thy - "[| : r^*; (a = b) ==> P; \ -\ !!y.[| : r^*; : r |] ==> P \ -\ |] ==> P"; -by (subgoal_tac "(a::'a) = b | (? y. : r^* & : r)" 1); -by (rtac (major RS rtrancl_induct) 2); -by (fast_tac (set_cs addIs prems) 2); -by (fast_tac (set_cs addIs prems) 2); -by (REPEAT (eresolve_tac ([asm_rl,exE,disjE,conjE]@prems) 1)); -qed "rtranclE"; - - -(**** The relation trancl ****) - -(** Conversions between trancl and rtrancl **) - -val [major] = goalw Trancl.thy [trancl_def] - " : r^+ ==> : r^*"; -by (resolve_tac [major RS compEpair] 1); -by (REPEAT (ares_tac [rtrancl_into_rtrancl] 1)); -qed "trancl_into_rtrancl"; - -(*r^+ contains r*) -val [prem] = goalw Trancl.thy [trancl_def] - "[| : r |] ==> : r^+"; -by (REPEAT (ares_tac [prem,compI,rtrancl_refl] 1)); -qed "r_into_trancl"; - -(*intro rule by definition: from rtrancl and r*) -val prems = goalw Trancl.thy [trancl_def] - "[| : r^*; : r |] ==> : r^+"; -by (REPEAT (resolve_tac ([compI]@prems) 1)); -qed "rtrancl_into_trancl1"; - -(*intro rule from r and rtrancl*) -val prems = goal Trancl.thy - "[| : r; : r^* |] ==> : r^+"; -by (resolve_tac (prems RL [rtranclE]) 1); -by (etac subst 1); -by (resolve_tac (prems RL [r_into_trancl]) 1); -by (rtac (trans_rtrancl RS transD RS rtrancl_into_trancl1) 1); -by (REPEAT (ares_tac (prems@[r_into_rtrancl]) 1)); -qed "rtrancl_into_trancl2"; - -(*elimination of r^+ -- NOT an induction rule*) -val major::prems = goal Trancl.thy - "[| : r^+; \ -\ : r ==> P; \ -\ !!y.[| : r^+; : r |] ==> P \ -\ |] ==> P"; -by (subgoal_tac " : r | (? y. : r^+ & : r)" 1); -by (REPEAT (eresolve_tac ([asm_rl,disjE,exE,conjE]@prems) 1)); -by (rtac (rewrite_rule [trancl_def] major RS compEpair) 1); -by (etac rtranclE 1); -by (fast_tac comp_cs 1); -by (fast_tac (comp_cs addSIs [rtrancl_into_trancl1]) 1); -qed "tranclE"; - -(*Transitivity of r^+. - Proved by unfolding since it uses transitivity of rtrancl. *) -goalw Trancl.thy [trancl_def] "trans(r^+)"; -by (rtac transI 1); -by (REPEAT (etac compEpair 1)); -by (rtac (rtrancl_into_rtrancl RS (trans_rtrancl RS transD RS compI)) 1); -by (REPEAT (assume_tac 1)); -qed "trans_trancl"; - -val prems = goal Trancl.thy - "[| : r; : r^+ |] ==> : r^+"; -by (rtac (r_into_trancl RS (trans_trancl RS transD)) 1); -by (resolve_tac prems 1); -by (resolve_tac prems 1); -qed "trancl_into_trancl2"; - - -val major::prems = goal Trancl.thy - "[| : r^*; r <= Sigma(A,%x.A) |] ==> a=b | a:A"; -by (cut_facts_tac prems 1); -by (rtac (major RS rtrancl_induct) 1); -by (rtac (refl RS disjI1) 1); -by (fast_tac (comp_cs addSEs [SigmaE2]) 1); -qed "trancl_subset_Sigma_lemma"; - -goalw Trancl.thy [trancl_def] - "!!r. r <= Sigma(A,%x.A) ==> trancl(r) <= Sigma(A,%x.A)"; -by (fast_tac (comp_cs addSDs [trancl_subset_Sigma_lemma]) 1); -qed "trancl_subset_Sigma"; - -val prod_ss = prod_ss addsimps [pair_in_id_conv];