diff -r 651028e34b5d -r 01dcd9b926bf src/HOL/MicroJava/BV/Kildall.thy --- a/src/HOL/MicroJava/BV/Kildall.thy Fri Dec 04 11:44:57 2009 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,498 +0,0 @@ -(* Title: HOL/MicroJava/BV/Kildall.thy - ID: $Id$ - Author: Tobias Nipkow, Gerwin Klein - Copyright 2000 TUM - -Kildall's algorithm -*) - -header {* \isaheader{Kildall's Algorithm}\label{sec:Kildall} *} - -theory Kildall -imports SemilatAlg While_Combinator -begin - - -consts - iter :: "'s binop \ 's step_type \ - 's list \ nat set \ 's list \ nat set" - propa :: "'s binop \ (nat \ 's) list \ 's list \ nat set \ 's list * nat set" - -primrec -"propa f [] ss w = (ss,w)" -"propa f (q'#qs) ss w = (let (q,t) = q'; - u = t +_f ss!q; - w' = (if u = ss!q then w else insert q w) - in propa f qs (ss[q := u]) w')" - -defs iter_def: -"iter f step ss w == - while (%(ss,w). w \ {}) - (%(ss,w). let p = SOME p. p \ w - in propa f (step p (ss!p)) ss (w-{p})) - (ss,w)" - -constdefs - unstables :: "'s ord \ 's step_type \ 's list \ nat set" -"unstables r step ss == {p. p < size ss \ \stable r step ss p}" - - kildall :: "'s ord \ 's binop \ 's step_type \ 's list \ 's list" -"kildall r f step ss == fst(iter f step ss (unstables r step ss))" - -consts merges :: "'s binop \ (nat \ 's) list \ 's list \ 's list" -primrec -"merges f [] ss = ss" -"merges f (p'#ps) ss = (let (p,s) = p' in merges f ps (ss[p := s +_f ss!p]))" - - -lemmas [simp] = Let_def Semilat.le_iff_plus_unchanged [OF Semilat.intro, symmetric] - - -lemma (in Semilat) nth_merges: - "\ss. \p < length ss; ss \ list n A; \(p,t)\set ps. p t\A \ \ - (merges f ps ss)!p = map snd [(p',t') \ ps. p'=p] ++_f ss!p" - (is "\ss. \_; _; ?steptype ps\ \ ?P ss ps") -proof (induct ps) - show "\ss. ?P ss []" by simp - - fix ss p' ps' - assume ss: "ss \ list n A" - assume l: "p < length ss" - assume "?steptype (p'#ps')" - then obtain a b where - p': "p'=(a,b)" and ab: "aA" and ps': "?steptype ps'" - by (cases p') auto - assume "\ss. p< length ss \ ss \ list n A \ ?steptype ps' \ ?P ss ps'" - from this [OF _ _ ps'] have IH: "\ss. ss \ list n A \ p < length ss \ ?P ss ps'" . - - from ss ab - have "ss[a := b +_f ss!a] \ list n A" by (simp add: closedD) - moreover - from calculation l - have "p < length (ss[a := b +_f ss!a])" by simp - ultimately - have "?P (ss[a := b +_f ss!a]) ps'" by (rule IH) - with p' l - show "?P ss (p'#ps')" by simp -qed - - -(** merges **) - -lemma length_merges [rule_format, simp]: - "\ss. size(merges f ps ss) = size ss" - by (induct_tac ps, auto) - - -lemma (in Semilat) merges_preserves_type_lemma: -shows "\xs. xs \ list n A \ (\(p,x) \ set ps. p x\A) - \ merges f ps xs \ list n A" -apply (insert closedI) -apply (unfold closed_def) -apply (induct_tac ps) - apply simp -apply clarsimp -done - -lemma (in Semilat) merges_preserves_type [simp]: - "\ xs \ list n A; \(p,x) \ set ps. p x\A \ - \ merges f ps xs \ list n A" -by (simp add: merges_preserves_type_lemma) - -lemma (in Semilat) merges_incr_lemma: - "\xs. xs \ list n A \ (\(p,x)\set ps. p x \ A) \ xs <=[r] merges f ps xs" -apply (induct_tac ps) - apply simp -apply simp -apply clarify -apply (rule order_trans) - apply simp - apply (erule list_update_incr) - apply simp - apply simp -apply (blast intro!: listE_set intro: closedD listE_length [THEN nth_in]) -done - -lemma (in Semilat) merges_incr: - "\ xs \ list n A; \(p,x)\set ps. p x \ A \ - \ xs <=[r] merges f ps xs" - by (simp add: merges_incr_lemma) - - -lemma (in Semilat) merges_same_conv [rule_format]: - "(\xs. xs \ list n A \ (\(p,x)\set ps. p x\A) \ - (merges f ps xs = xs) = (\(p,x)\set ps. x <=_r xs!p))" - apply (induct_tac ps) - apply simp - apply clarsimp - apply (rename_tac p x ps xs) - apply (rule iffI) - apply (rule context_conjI) - apply (subgoal_tac "xs[p := x +_f xs!p] <=[r] xs") - apply (drule_tac p = p in le_listD) - apply simp - apply simp - apply (erule subst, rule merges_incr) - apply (blast intro!: listE_set intro: closedD listE_length [THEN nth_in]) - apply clarify - apply (rule conjI) - apply simp - apply (blast dest: boundedD) - apply blast - apply clarify - apply (erule allE) - apply (erule impE) - apply assumption - apply (drule bspec) - apply assumption - apply (simp add: le_iff_plus_unchanged [THEN iffD1] list_update_same_conv [THEN iffD2]) - apply blast - apply clarify - apply (simp add: le_iff_plus_unchanged [THEN iffD1] list_update_same_conv [THEN iffD2]) - done - - -lemma (in Semilat) list_update_le_listI [rule_format]: - "set xs <= A \ set ys <= A \ xs <=[r] ys \ p < size xs \ - x <=_r ys!p \ x\A \ xs[p := x +_f xs!p] <=[r] ys" - apply(insert semilat) - apply (unfold Listn.le_def lesub_def semilat_def) - apply (simp add: list_all2_conv_all_nth nth_list_update) - done - -lemma (in Semilat) merges_pres_le_ub: - assumes "set ts <= A" and "set ss <= A" - and "\(p,t)\set ps. t <=_r ts!p \ t \ A \ p < size ts" and "ss <=[r] ts" - shows "merges f ps ss <=[r] ts" -proof - - { fix t ts ps - have - "\qs. \set ts <= A; \(p,t)\set ps. t <=_r ts!p \ t \ A \ p< size ts \ \ - set qs <= set ps \ - (\ss. set ss <= A \ ss <=[r] ts \ merges f qs ss <=[r] ts)" - apply (induct_tac qs) - apply simp - apply (simp (no_asm_simp)) - apply clarify - apply (rotate_tac -2) - apply simp - apply (erule allE, erule impE, erule_tac [2] mp) - apply (drule bspec, assumption) - apply (simp add: closedD) - apply (drule bspec, assumption) - apply (simp add: list_update_le_listI) - done - } note this [dest] - - from prems show ?thesis by blast -qed - - -(** propa **) - - -lemma decomp_propa: - "\ss w. (\(q,t)\set qs. q < size ss) \ - propa f qs ss w = - (merges f qs ss, {q. \t. (q,t)\set qs \ t +_f ss!q \ ss!q} Un w)" - apply (induct qs) - apply simp - apply (simp (no_asm)) - apply clarify - apply simp - apply (rule conjI) - apply blast - apply (simp add: nth_list_update) - apply blast - done - -(** iter **) - -lemma (in Semilat) stable_pres_lemma: -shows "\pres_type step n A; bounded step n; - ss \ list n A; p \ w; \q\w. q < n; - \q. q < n \ q \ w \ stable r step ss q; q < n; - \s'. (q,s') \ set (step p (ss ! p)) \ s' +_f ss ! q = ss ! q; - q \ w \ q = p \ - \ stable r step (merges f (step p (ss!p)) ss) q" - apply (unfold stable_def) - apply (subgoal_tac "\s'. (q,s') \ set (step p (ss!p)) \ s' : A") - prefer 2 - apply clarify - apply (erule pres_typeD) - prefer 3 apply assumption - apply (rule listE_nth_in) - apply assumption - apply simp - apply simp - apply simp - apply clarify - apply (subst nth_merges) - apply simp - apply (blast dest: boundedD) - apply assumption - apply clarify - apply (rule conjI) - apply (blast dest: boundedD) - apply (erule pres_typeD) - prefer 3 apply assumption - apply simp - apply simp -apply(subgoal_tac "q < length ss") -prefer 2 apply simp - apply (frule nth_merges [of q _ _ "step p (ss!p)"]) (* fixme: why does method subst not work?? *) -apply assumption - apply clarify - apply (rule conjI) - apply (blast dest: boundedD) - apply (erule pres_typeD) - prefer 3 apply assumption - apply simp - apply simp - apply (drule_tac P = "\x. (a, b) \ set (step q x)" in subst) - apply assumption - - apply (simp add: plusplus_empty) - apply (cases "q \ w") - apply simp - apply (rule ub1') - apply (rule semilat) - apply clarify - apply (rule pres_typeD) - apply assumption - prefer 3 apply assumption - apply (blast intro: listE_nth_in dest: boundedD) - apply (blast intro: pres_typeD dest: boundedD) - apply (blast intro: listE_nth_in dest: boundedD) - apply assumption - - apply simp - apply (erule allE, erule impE, assumption, erule impE, assumption) - apply (rule order_trans) - apply simp - defer - apply (rule pp_ub2)(* - apply assumption*) - apply simp - apply clarify - apply simp - apply (rule pres_typeD) - apply assumption - prefer 3 apply assumption - apply (blast intro: listE_nth_in dest: boundedD) - apply (blast intro: pres_typeD dest: boundedD) - apply (blast intro: listE_nth_in dest: boundedD) - apply blast - done - - -lemma (in Semilat) merges_bounded_lemma: - "\ mono r step n A; bounded step n; - \(p',s') \ set (step p (ss!p)). s' \ A; ss \ list n A; ts \ list n A; p < n; - ss <=[r] ts; \p. p < n \ stable r step ts p \ - \ merges f (step p (ss!p)) ss <=[r] ts" - apply (unfold stable_def) - apply (rule merges_pres_le_ub) - apply simp - apply simp - prefer 2 apply assumption - - apply clarsimp - apply (drule boundedD, assumption+) - apply (erule allE, erule impE, assumption) - apply (drule bspec, assumption) - apply simp - - apply (drule monoD [of _ _ _ _ p "ss!p" "ts!p"]) - apply assumption - apply simp - apply (simp add: le_listD) - - apply (drule lesub_step_typeD, assumption) - apply clarify - apply (drule bspec, assumption) - apply simp - apply (blast intro: order_trans) - done - -lemma termination_lemma: - assumes semilat: "semilat (A, r, f)" - shows "\ ss \ list n A; \(q,t)\set qs. q t\A; p\w \ \ - ss <[r] merges f qs ss \ - merges f qs ss = ss \ {q. \t. (q,t)\set qs \ t +_f ss!q \ ss!q} Un (w-{p}) < w" (is "PROP ?P") -proof - - interpret Semilat A r f using assms by (rule Semilat.intro) - show "PROP ?P" apply(insert semilat) - apply (unfold lesssub_def) - apply (simp (no_asm_simp) add: merges_incr) - apply (rule impI) - apply (rule merges_same_conv [THEN iffD1, elim_format]) - apply assumption+ - defer - apply (rule sym, assumption) - defer apply simp - apply (subgoal_tac "\q t. \((q, t) \ set qs \ t +_f ss ! q \ ss ! q)") - apply (blast intro!: psubsetI elim: equalityE) - apply clarsimp - apply (drule bspec, assumption) - apply (drule bspec, assumption) - apply clarsimp - done -qed - -lemma iter_properties[rule_format]: - assumes semilat: "semilat (A, r, f)" - shows "\ acc r ; pres_type step n A; mono r step n A; - bounded step n; \p\w0. p < n; ss0 \ list n A; - \p w0 \ stable r step ss0 p \ \ - iter f step ss0 w0 = (ss',w') - \ - ss' \ list n A \ stables r step ss' \ ss0 <=[r] ss' \ - (\ts\list n A. ss0 <=[r] ts \ stables r step ts \ ss' <=[r] ts)" - (is "PROP ?P") -proof - - interpret Semilat A r f using assms by (rule Semilat.intro) - show "PROP ?P" apply(insert semilat) -apply (unfold iter_def stables_def) -apply (rule_tac P = "%(ss,w). - ss \ list n A \ (\p w \ stable r step ss p) \ ss0 <=[r] ss \ - (\ts\list n A. ss0 <=[r] ts \ stables r step ts \ ss <=[r] ts) \ - (\p\w. p < n)" and - r = "{(ss',ss) . ss <[r] ss'} <*lex*> finite_psubset" - in while_rule) - --- "Invariant holds initially:" -apply (simp add:stables_def) - --- "Invariant is preserved:" -apply(simp add: stables_def split_paired_all) -apply(rename_tac ss w) -apply(subgoal_tac "(SOME p. p \ w) \ w") - prefer 2; apply (fast intro: someI) -apply(subgoal_tac "\(q,t) \ set (step (SOME p. p \ w) (ss ! (SOME p. p \ w))). q < length ss \ t \ A") - prefer 2 - apply clarify - apply (rule conjI) - apply(clarsimp, blast dest!: boundedD) - apply (erule pres_typeD) - prefer 3 - apply assumption - apply (erule listE_nth_in) - apply simp - apply simp -apply (subst decomp_propa) - apply fast -apply simp -apply (rule conjI) - apply (rule merges_preserves_type) - apply blast - apply clarify - apply (rule conjI) - apply(clarsimp, fast dest!: boundedD) - apply (erule pres_typeD) - prefer 3 - apply assumption - apply (erule listE_nth_in) - apply blast - apply blast -apply (rule conjI) - apply clarify - apply (blast intro!: stable_pres_lemma) -apply (rule conjI) - apply (blast intro!: merges_incr intro: le_list_trans) -apply (rule conjI) - apply clarsimp - apply (blast intro!: merges_bounded_lemma) -apply (blast dest!: boundedD) - - --- "Postcondition holds upon termination:" -apply(clarsimp simp add: stables_def split_paired_all) - --- "Well-foundedness of the termination relation:" -apply (rule wf_lex_prod) - apply (insert orderI [THEN acc_le_listI]) - apply (simp add: acc_def lesssub_def wfP_wf_eq [symmetric]) -apply (rule wf_finite_psubset) - --- "Loop decreases along termination relation:" -apply(simp add: stables_def split_paired_all) -apply(rename_tac ss w) -apply(subgoal_tac "(SOME p. p \ w) \ w") - prefer 2; apply (fast intro: someI) -apply(subgoal_tac "\(q,t) \ set (step (SOME p. p \ w) (ss ! (SOME p. p \ w))). q < length ss \ t \ A") - prefer 2 - apply clarify - apply (rule conjI) - apply(clarsimp, blast dest!: boundedD) - apply (erule pres_typeD) - prefer 3 - apply assumption - apply (erule listE_nth_in) - apply blast - apply blast -apply (subst decomp_propa) - apply blast -apply clarify -apply (simp del: listE_length - add: lex_prod_def finite_psubset_def - bounded_nat_set_is_finite) -apply (rule termination_lemma) -apply assumption+ -defer -apply assumption -apply clarsimp -done - -qed - -lemma kildall_properties: -assumes semilat: "semilat (A, r, f)" -shows "\ acc r; pres_type step n A; mono r step n A; - bounded step n; ss0 \ list n A \ \ - kildall r f step ss0 \ list n A \ - stables r step (kildall r f step ss0) \ - ss0 <=[r] kildall r f step ss0 \ - (\ts\list n A. ss0 <=[r] ts \ stables r step ts \ - kildall r f step ss0 <=[r] ts)" - (is "PROP ?P") -proof - - interpret Semilat A r f using assms by (rule Semilat.intro) - show "PROP ?P" -apply (unfold kildall_def) -apply(case_tac "iter f step ss0 (unstables r step ss0)") -apply(simp) -apply (rule iter_properties) -apply (simp_all add: unstables_def stable_def) -apply (rule semilat) -done -qed - -lemma is_bcv_kildall: -assumes semilat: "semilat (A, r, f)" -shows "\ acc r; top r T; pres_type step n A; bounded step n; mono r step n A \ - \ is_bcv r T step n A (kildall r f step)" - (is "PROP ?P") -proof - - interpret Semilat A r f using assms by (rule Semilat.intro) - show "PROP ?P" -apply(unfold is_bcv_def wt_step_def) -apply(insert semilat kildall_properties[of A]) -apply(simp add:stables_def) -apply clarify -apply(subgoal_tac "kildall r f step ss \ list n A") - prefer 2 apply (simp(no_asm_simp)) -apply (rule iffI) - apply (rule_tac x = "kildall r f step ss" in bexI) - apply (rule conjI) - apply (blast) - apply (simp (no_asm_simp)) - apply(assumption) -apply clarify -apply(subgoal_tac "kildall r f step ss!p <=_r ts!p") - apply simp -apply (blast intro!: le_listD less_lengthI) -done -qed - -end