author | lcp |
Thu, 06 Apr 1995 11:49:42 +0200 | |
changeset 246 | 0f9230a24164 |
parent 48 | 21291189b51e |
permissions | -rw-r--r-- |
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(* Title: Substitutions/subst.ML |
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Author: Martin Coen, Cambridge University Computer Laboratory |
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Copyright 1993 University of Cambridge |
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For subst.thy. |
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*) |
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open Subst; |
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(***********) |
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val subst_defs = [subst_def,comp_def,sdom_def]; |
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val raw_subst_ss = utlemmas_ss addsimps al_rews; |
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local fun mk_thm s = prove_goalw Subst.thy subst_defs s |
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(fn _ => [simp_tac raw_subst_ss 1]) |
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in val subst_rews = map mk_thm |
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["Const(c) <| al = Const(c)", |
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"Comb(t,u) <| al = Comb(t <| al, u <| al)", |
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"Nil <> bl = bl", |
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21291189b51e
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parents:
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"<a,b>#al <> bl = <a,b <| bl> # (al <> bl)", |
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"sdom(Nil) = {}", |
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"sdom(<a,b>#al) = if(Var(a)=b,sdom(al) Int Compl({a}),sdom(al) Un {a})" |
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]; |
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(* This rewrite isn't always desired *) |
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val Var_subst = mk_thm "Var(x) <| al = assoc(x,Var(x),al)"; |
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end; |
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val subst_ss = raw_subst_ss addsimps subst_rews; |
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(**** Substitutions ****) |
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goal Subst.thy "t <| Nil = t"; |
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by (uterm_ind_tac "t" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [Var_subst]))); |
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val subst_Nil = result(); |
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goal Subst.thy "t <: u --> t <| s <: u <| s"; |
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by (uterm_ind_tac "u" 1); |
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by (ALLGOALS (asm_simp_tac subst_ss)); |
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val subst_mono = result() RS mp; |
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goal Subst.thy "~ (Var(v) <: t) --> t <| <v,t <| s>#s = t <| s"; |
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by (imp_excluded_middle_tac "t = Var(v)" 1); |
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by (res_inst_tac [("P", |
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"%x.~x=Var(v) --> ~(Var(v) <: x) --> x <| <v,t<|s>#s=x<|s")] |
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uterm_induct 2); |
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by (ALLGOALS (simp_tac (subst_ss addsimps [Var_subst]))); |
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by (fast_tac HOL_cs 1); |
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val Var_not_occs = result() RS mp; |
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goal Subst.thy |
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"(t <|r = t <|s) = (! v.v : vars_of(t) --> Var(v) <|r = Var(v) <|s)"; |
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by (uterm_ind_tac "t" 1); |
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by (REPEAT (etac rev_mp 3)); |
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by (ALLGOALS (asm_simp_tac subst_ss)); |
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by (ALLGOALS (fast_tac HOL_cs)); |
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val agreement = result(); |
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goal Subst.thy "~ v: vars_of(t) --> t <| <v,u>#s = t <| s"; |
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by(simp_tac(subst_ss addsimps [agreement,Var_subst] |
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setloop (split_tac [expand_if])) 1); |
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val repl_invariance = result() RS mp; |
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val asms = goal Subst.thy |
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changeset
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"v : vars_of(t) --> w : vars_of(t <| <v,Var(w)>#s)"; |
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by (uterm_ind_tac "t" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [Var_subst]))); |
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val Var_in_subst = result() RS mp; |
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(**** Equality between Substitutions ****) |
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goalw Subst.thy [subst_eq_def] "r =s= s = (! t.t <| r = t <| s)"; |
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by (simp_tac subst_ss 1); |
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val subst_eq_iff = result(); |
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local fun mk_thm s = prove_goal Subst.thy s |
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(fn prems => [cut_facts_tac prems 1, |
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REPEAT (etac rev_mp 1), |
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simp_tac (subst_ss addsimps [subst_eq_iff]) 1]) |
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in |
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val subst_refl = mk_thm "r = s ==> r =s= s"; |
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val subst_sym = mk_thm "r =s= s ==> s =s= r"; |
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val subst_trans = mk_thm "[| q =s= r; r =s= s |] ==> q =s= s"; |
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end; |
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val eq::prems = goalw Subst.thy [subst_eq_def] |
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"[| r =s= s; P(t <| r,u <| r) |] ==> P(t <| s,u <| s)"; |
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by (resolve_tac [eq RS spec RS subst] 1); |
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by (resolve_tac (prems RL [eq RS spec RS subst]) 1); |
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val subst_subst2 = result(); |
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val ssubst_subst2 = subst_sym RS subst_subst2; |
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(**** Composition of Substitutions ****) |
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goal Subst.thy "s <> Nil = s"; |
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by (alist_ind_tac "s" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [subst_Nil]))); |
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val comp_Nil = result(); |
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goal Subst.thy "(t <| r <> s) = (t <| r <| s)"; |
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by (uterm_ind_tac "t" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [Var_subst]))); |
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by (alist_ind_tac "r" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [Var_subst,subst_Nil] |
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setloop (split_tac [expand_if])))); |
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val subst_comp = result(); |
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goal Subst.thy "q <> r <> s =s= q <> (r <> s)"; |
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by (simp_tac (subst_ss addsimps [subst_eq_iff,subst_comp]) 1); |
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val comp_assoc = result(); |
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48
21291189b51e
changed "." to "$" and Cons to infix "#" to eliminate ambiguity
clasohm
parents:
0
diff
changeset
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goal Subst.thy "<w,Var(w) <| s>#s =s= s"; |
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by (rtac (allI RS (subst_eq_iff RS iffD2)) 1); |
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by (uterm_ind_tac "t" 1); |
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by (REPEAT (etac rev_mp 3)); |
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by (ALLGOALS (simp_tac (subst_ss addsimps[Var_subst] |
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setloop (split_tac [expand_if])))); |
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val Cons_trivial = result(); |
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val [prem] = goal Subst.thy "q <> r =s= s ==> t <| q <| r = t <| s"; |
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by (simp_tac (subst_ss addsimps [prem RS (subst_eq_iff RS iffD1), |
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subst_comp RS sym]) 1); |
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val comp_subst_subst = result(); |
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(**** Domain and range of Substitutions ****) |
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goal Subst.thy "(v : sdom(s)) = (~ Var(v) <| s = Var(v))"; |
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by (alist_ind_tac "s" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [Var_subst] |
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setloop (split_tac[expand_if])))); |
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by (fast_tac HOL_cs 1); |
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val sdom_iff = result(); |
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goalw Subst.thy [srange_def] |
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"v : srange(s) = (? w.w : sdom(s) & v : vars_of(Var(w) <| s))"; |
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by (fast_tac set_cs 1); |
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val srange_iff = result(); |
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goal Subst.thy "(t <| s = t) = (sdom(s) Int vars_of(t) = {})"; |
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by (uterm_ind_tac "t" 1); |
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by (REPEAT (etac rev_mp 3)); |
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by (ALLGOALS (simp_tac (subst_ss addsimps [sdom_iff,Var_subst]))); |
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by (ALLGOALS (fast_tac set_cs)); |
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val invariance = result(); |
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goal Subst.thy "v : sdom(s) --> ~v : srange(s) --> ~v : vars_of(t <| s)"; |
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by (uterm_ind_tac "t" 1); |
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by (imp_excluded_middle_tac "x : sdom(s)" 1); |
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by (ALLGOALS (asm_simp_tac (subst_ss addsimps [sdom_iff,srange_iff]))); |
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by (ALLGOALS (fast_tac set_cs)); |
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val Var_elim = result() RS mp RS mp; |
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val asms = goal Subst.thy |
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"[| v : sdom(s); v : vars_of(t <| s) |] ==> v : srange(s)"; |
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by (REPEAT (ares_tac (asms @ [Var_elim RS swap RS classical]) 1)); |
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val Var_elim2 = result(); |
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goal Subst.thy "v : vars_of(t <| s) --> v : srange(s) | v : vars_of(t)"; |
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by (uterm_ind_tac "t" 1); |
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by (REPEAT_SOME (etac rev_mp )); |
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by (ALLGOALS (simp_tac (subst_ss addsimps [sdom_iff,srange_iff]))); |
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by (REPEAT (step_tac (set_cs addIs [vars_var_iff RS iffD1 RS sym]) 1)); |
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by (etac notE 1); |
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by (etac subst 1); |
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by (ALLGOALS (fast_tac set_cs)); |
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val Var_intro = result() RS mp; |
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goal Subst.thy |
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"v : srange(s) --> (? w.w : sdom(s) & v : vars_of(Var(w) <| s))"; |
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by (simp_tac (subst_ss addsimps [srange_iff]) 1); |
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val srangeE = make_elim (result() RS mp); |
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val asms = goal Subst.thy |
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"sdom(s) Int srange(s) = {} = (! t.sdom(s) Int vars_of(t <| s) = {})"; |
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by (simp_tac subst_ss 1); |
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by (fast_tac (set_cs addIs [Var_elim2] addEs [srangeE]) 1); |
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val dom_range_disjoint = result(); |
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val asms = goal Subst.thy "~ u <| s = u --> (? x.x : sdom(s))"; |
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by (simp_tac (subst_ss addsimps [invariance]) 1); |
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by (fast_tac set_cs 1); |
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val subst_not_empty = result() RS mp; |