Nominal/Ex/LetInv.thy
branchNominal2-Isabelle2011-1
changeset 3071 11f6a561eb4b
parent 3070 4b4742aa43f2
child 3072 7eb352826b42
equal deleted inserted replaced
3070:4b4742aa43f2 3071:11f6a561eb4b
     1 theory Let
       
     2 imports "../Nominal2" 
       
     3 begin
       
     4 
       
     5 atom_decl name
       
     6 
       
     7 nominal_datatype trm =
       
     8   Var "name"
       
     9 | App "trm" "trm"
       
    10 | Lam x::"name" t::"trm"    binds  x in t
       
    11 | Let as::"assn" t::"trm"   binds "bn as" in t
       
    12 and assn =
       
    13   ANil
       
    14 | ACons "name" "trm" "assn"
       
    15 binder
       
    16   bn
       
    17 where
       
    18   "bn ANil = []"
       
    19 | "bn (ACons x t as) = (atom x) # (bn as)"
       
    20 
       
    21 print_theorems
       
    22 
       
    23 thm alpha_trm_raw_alpha_assn_raw_alpha_bn_raw.intros
       
    24 thm bn_raw.simps
       
    25 thm permute_bn_raw.simps
       
    26 thm trm_assn.perm_bn_alpha
       
    27 thm trm_assn.permute_bn
       
    28 
       
    29 thm trm_assn.fv_defs
       
    30 thm trm_assn.eq_iff 
       
    31 thm trm_assn.bn_defs
       
    32 thm trm_assn.bn_inducts
       
    33 thm trm_assn.perm_simps
       
    34 thm trm_assn.induct
       
    35 thm trm_assn.inducts
       
    36 thm trm_assn.distinct
       
    37 thm trm_assn.supp
       
    38 thm trm_assn.fresh
       
    39 thm trm_assn.exhaust
       
    40 thm trm_assn.strong_exhaust
       
    41 thm trm_assn.perm_bn_simps
       
    42 
       
    43 lemma alpha_bn_inducts_raw[consumes 1]:
       
    44   "\<lbrakk>alpha_bn_raw a b; P3 ANil_raw ANil_raw;
       
    45  \<And>trm_raw trm_rawa assn_raw assn_rawa name namea.
       
    46     \<lbrakk>alpha_trm_raw trm_raw trm_rawa; alpha_bn_raw assn_raw assn_rawa;
       
    47      P3 assn_raw assn_rawa\<rbrakk>
       
    48     \<Longrightarrow> P3 (ACons_raw name trm_raw assn_raw)
       
    49         (ACons_raw namea trm_rawa assn_rawa)\<rbrakk> \<Longrightarrow> P3 a b"
       
    50   by (erule alpha_trm_raw_alpha_assn_raw_alpha_bn_raw.inducts(3)[of _ _ "\<lambda>x y. True" _ "\<lambda>x y. True", simplified]) auto
       
    51 
       
    52 lemmas alpha_bn_inducts[consumes 1] = alpha_bn_inducts_raw[quot_lifted]
       
    53 
       
    54 
       
    55 
       
    56 lemma alpha_bn_refl: "alpha_bn x x"
       
    57   by (induct x rule: trm_assn.inducts(2))
       
    58      (rule TrueI, auto simp add: trm_assn.eq_iff)
       
    59 lemma alpha_bn_sym: "alpha_bn x y \<Longrightarrow> alpha_bn y x"
       
    60   sorry
       
    61 lemma alpha_bn_trans: "alpha_bn x y \<Longrightarrow> alpha_bn y z \<Longrightarrow> alpha_bn x z"
       
    62   sorry
       
    63 
       
    64 lemma bn_inj[rule_format]:
       
    65   assumes a: "alpha_bn x y"
       
    66   shows "bn x = bn y \<longrightarrow> x = y"
       
    67   by (rule alpha_bn_inducts[OF a]) (simp_all add: trm_assn.bn_defs)
       
    68 
       
    69 lemma bn_inj2:
       
    70   assumes a: "alpha_bn x y"
       
    71   shows "\<And>q r. (q \<bullet> bn x) = (r \<bullet> bn y) \<Longrightarrow> permute_bn q x = permute_bn r y"
       
    72 using a
       
    73 apply(induct rule: alpha_bn_inducts)
       
    74 apply(simp add: trm_assn.perm_bn_simps)
       
    75 apply(simp add: trm_assn.perm_bn_simps)
       
    76 apply(simp add: trm_assn.bn_defs)
       
    77 apply(simp add: atom_eqvt)
       
    78 done
       
    79 
       
    80 lemma Abs_lst_fcb2:
       
    81   fixes as bs :: "atom list"
       
    82     and x y :: "'b :: fs"
       
    83     and c::"'c::fs"
       
    84   assumes eq: "[as]lst. x = [bs]lst. y"
       
    85   and fcb1: "(set as) \<sharp>* c \<Longrightarrow> (set as) \<sharp>* f as x c"
       
    86   and fresh1: "set as \<sharp>* c"
       
    87   and fresh2: "set bs \<sharp>* c"
       
    88   and perm1: "\<And>p. supp p \<sharp>* c \<Longrightarrow> p \<bullet> (f as x c) = f (p \<bullet> as) (p \<bullet> x) c"
       
    89   and perm2: "\<And>p. supp p \<sharp>* c \<Longrightarrow> p \<bullet> (f bs y c) = f (p \<bullet> bs) (p \<bullet> y) c"
       
    90   shows "f as x c = f bs y c"
       
    91 proof -
       
    92   have "supp (as, x, c) supports (f as x c)"
       
    93     unfolding  supports_def fresh_def[symmetric]
       
    94     by (simp add: fresh_Pair perm1 fresh_star_def supp_swap swap_fresh_fresh)
       
    95   then have fin1: "finite (supp (f as x c))"
       
    96     by (auto intro: supports_finite simp add: finite_supp)
       
    97   have "supp (bs, y, c) supports (f bs y c)"
       
    98     unfolding  supports_def fresh_def[symmetric]
       
    99     by (simp add: fresh_Pair perm2 fresh_star_def supp_swap swap_fresh_fresh)
       
   100   then have fin2: "finite (supp (f bs y c))"
       
   101     by (auto intro: supports_finite simp add: finite_supp)
       
   102   obtain q::"perm" where 
       
   103     fr1: "(q \<bullet> (set as)) \<sharp>* (x, c, f as x c, f bs y c)" and 
       
   104     fr2: "supp q \<sharp>* Abs_lst as x" and 
       
   105     inc: "supp q \<subseteq> (set as) \<union> q \<bullet> (set as)"
       
   106     using at_set_avoiding3[where xs="set as" and c="(x, c, f as x c, f bs y c)" and x="[as]lst. x"]  
       
   107       fin1 fin2
       
   108     by (auto simp add: supp_Pair finite_supp Abs_fresh_star dest: fresh_star_supp_conv)
       
   109   have "Abs_lst (q \<bullet> as) (q \<bullet> x) = q \<bullet> Abs_lst as x" by simp
       
   110   also have "\<dots> = Abs_lst as x"
       
   111     by (simp only: fr2 perm_supp_eq)
       
   112   finally have "Abs_lst (q \<bullet> as) (q \<bullet> x) = Abs_lst bs y" using eq by simp
       
   113   then obtain r::perm where 
       
   114     qq1: "q \<bullet> x = r \<bullet> y" and 
       
   115     qq2: "q \<bullet> as = r \<bullet> bs" and 
       
   116     qq3: "supp r \<subseteq> (q \<bullet> (set as)) \<union> set bs"
       
   117     apply(drule_tac sym)
       
   118     apply(simp only: Abs_eq_iff2 alphas)
       
   119     apply(erule exE)
       
   120     apply(erule conjE)+
       
   121     apply(drule_tac x="p" in meta_spec)
       
   122     apply(simp add: set_eqvt)
       
   123     apply(blast)
       
   124     done
       
   125   have "(set as) \<sharp>* f as x c" 
       
   126     apply(rule fcb1)
       
   127     apply(rule fresh1)
       
   128     done
       
   129   then have "q \<bullet> ((set as) \<sharp>* f as x c)"
       
   130     by (simp add: permute_bool_def)
       
   131   then have "set (q \<bullet> as) \<sharp>* f (q \<bullet> as) (q \<bullet> x) c"
       
   132     apply(simp add: fresh_star_eqvt set_eqvt)
       
   133     apply(subst (asm) perm1)
       
   134     using inc fresh1 fr1
       
   135     apply(auto simp add: fresh_star_def fresh_Pair)
       
   136     done
       
   137   then have "set (r \<bullet> bs) \<sharp>* f (r \<bullet> bs) (r \<bullet> y) c" using qq1 qq2 by simp
       
   138   then have "r \<bullet> ((set bs) \<sharp>* f bs y c)"
       
   139     apply(simp add: fresh_star_eqvt set_eqvt)
       
   140     apply(subst (asm) perm2[symmetric])
       
   141     using qq3 fresh2 fr1
       
   142     apply(auto simp add: set_eqvt fresh_star_def fresh_Pair)
       
   143     done
       
   144   then have fcb2: "(set bs) \<sharp>* f bs y c" by (simp add: permute_bool_def)
       
   145   have "f as x c = q \<bullet> (f as x c)"
       
   146     apply(rule perm_supp_eq[symmetric])
       
   147     using inc fcb1[OF fresh1] fr1 by (auto simp add: fresh_star_def)
       
   148   also have "\<dots> = f (q \<bullet> as) (q \<bullet> x) c" 
       
   149     apply(rule perm1)
       
   150     using inc fresh1 fr1 by (auto simp add: fresh_star_def)
       
   151   also have "\<dots> = f (r \<bullet> bs) (r \<bullet> y) c" using qq1 qq2 by simp
       
   152   also have "\<dots> = r \<bullet> (f bs y c)"
       
   153     apply(rule perm2[symmetric])
       
   154     using qq3 fresh2 fr1 by (auto simp add: fresh_star_def)
       
   155   also have "... = f bs y c"
       
   156     apply(rule perm_supp_eq)
       
   157     using qq3 fr1 fcb2 by (auto simp add: fresh_star_def)
       
   158   finally show ?thesis by simp
       
   159 qed
       
   160 
       
   161 lemma Abs_lst1_fcb2:
       
   162   fixes a b :: "atom"
       
   163     and x y :: "'b :: fs"
       
   164     and c::"'c :: fs"
       
   165   assumes e: "(Abs_lst [a] x) = (Abs_lst [b] y)"
       
   166   and fcb1: "a \<sharp> c \<Longrightarrow> a \<sharp> f a x c"
       
   167   and fresh: "{a, b} \<sharp>* c"
       
   168   and perm1: "\<And>p. supp p \<sharp>* c \<Longrightarrow> p \<bullet> (f a x c) = f (p \<bullet> a) (p \<bullet> x) c"
       
   169   and perm2: "\<And>p. supp p \<sharp>* c \<Longrightarrow> p \<bullet> (f b y c) = f (p \<bullet> b) (p \<bullet> y) c"
       
   170   shows "f a x c = f b y c"
       
   171 using e
       
   172 apply(drule_tac Abs_lst_fcb2[where c="c" and f="\<lambda>(as::atom list) . f (hd as)"])
       
   173 apply(simp_all)
       
   174 using fcb1 fresh perm1 perm2
       
   175 apply(simp_all add: fresh_star_def)
       
   176 done
       
   177 
       
   178 
       
   179 function
       
   180   apply_assn2 :: "(trm \<Rightarrow> trm) \<Rightarrow> assn \<Rightarrow> assn"
       
   181 where
       
   182   "apply_assn2 f ANil = ANil"
       
   183 | "apply_assn2 f (ACons x t as) = ACons x (f t) (apply_assn2 f as)"
       
   184   apply(case_tac x)
       
   185   apply(case_tac b rule: trm_assn.exhaust(2))
       
   186   apply(simp_all)
       
   187   apply(blast)
       
   188   done
       
   189 
       
   190 termination by lexicographic_order
       
   191 
       
   192 lemma apply_assn_eqvt[eqvt]:
       
   193   "p \<bullet> (apply_assn2 f a) = apply_assn2 (p \<bullet> f) (p \<bullet> a)"
       
   194   apply(induct f a rule: apply_assn2.induct)
       
   195   apply simp_all
       
   196   apply(perm_simp)
       
   197   apply rule
       
   198   done
       
   199 
       
   200 lemma
       
   201   fixes x y :: "'a :: fs"
       
   202   shows "[a # as]lst. x = [b # bs]lst. y \<Longrightarrow> [[a]]lst. [as]lst. x = [[b]]lst. [bs]lst. y"
       
   203   apply (simp add: Abs_eq_iff)
       
   204   apply (elim exE)
       
   205   apply (rule_tac x="p" in exI)
       
   206   apply (simp add: alphas)
       
   207   apply clarify
       
   208   apply rule
       
   209   apply (simp add: supp_Abs)
       
   210   apply blast
       
   211   apply (simp add: supp_Abs fresh_star_def)
       
   212   apply blast
       
   213   done
       
   214 
       
   215 lemma
       
   216   assumes neq: "a \<noteq> b" "sort_of a = sort_of b"
       
   217   shows "[[a]]lst. [[a]]lst. a = [[a]]lst. [[b]]lst. b \<and> [[a, a]]lst. a \<noteq> [[a, b]]lst. b"
       
   218   apply (simp add: Abs1_eq_iff)
       
   219   apply rule
       
   220   apply (simp add: Abs_eq_iff alphas supp_atom fresh_star_def)
       
   221   apply (rule_tac x="(a \<rightleftharpoons> b)" in exI)
       
   222   apply (simp add: neq)
       
   223   apply (simp add: Abs_eq_iff alphas supp_atom fresh_star_def neq)
       
   224   done
       
   225 
       
   226 nominal_primrec
       
   227     subst  :: "name \<Rightarrow> trm \<Rightarrow> trm \<Rightarrow> trm"
       
   228 where
       
   229   "subst s t (Var x) = (if (s = x) then t else (Var x))"
       
   230 | "subst s t (App l r) = App (subst s t l) (subst s t r)"
       
   231 | "atom v \<sharp> (s, t) \<Longrightarrow> subst s t (Lam v b) = Lam v (subst s t b)"
       
   232 | "set (bn as) \<sharp>* (s, t) \<Longrightarrow> subst s t (Let as b) = Let (apply_assn2 (subst s t) as) (subst s t b)"
       
   233   apply (simp only: eqvt_def subst_graph_def)
       
   234   apply (rule, perm_simp, rule)
       
   235   apply (rule TrueI)
       
   236   apply (case_tac x)
       
   237   apply (rule_tac y="c" and c="(a,b)" in trm_assn.strong_exhaust(1))
       
   238   apply (auto simp add: fresh_star_def)[3]
       
   239   apply (drule_tac x="assn" in meta_spec)
       
   240   apply (simp add: Abs1_eq_iff alpha_bn_refl)
       
   241   apply auto[7]
       
   242   prefer 2
       
   243   apply(simp)
       
   244   thm subst_sumC_def
       
   245   thm THE_default_def
       
   246   thm theI
       
   247   apply (erule_tac c="(sa, ta)" in Abs_lst1_fcb2)
       
   248   apply (simp add: Abs_fresh_iff)
       
   249   apply (simp add: fresh_star_def)
       
   250   apply (simp_all add: fresh_star_Pair_elim perm_supp_eq eqvt_at_def)[2]
       
   251   apply (subgoal_tac "apply_assn2 (\<lambda>x2\<Colon>trm. subst_sumC (sa, ta, x2)) asa
       
   252     = apply_assn2 (\<lambda>x2\<Colon>trm. subst_sumC (sa, ta, x2)) as")
       
   253   prefer 2
       
   254   apply (erule alpha_bn_inducts)
       
   255   apply simp
       
   256   apply (simp only: apply_assn2.simps)
       
   257   apply simp
       
   258 --"We know nothing about names; not true; but we can apply fcb2"
       
   259   defer
       
   260   apply (simp only: )
       
   261   apply (erule_tac c="(sa, ta)" in Abs_lst_fcb2)
       
   262 --"We again need induction for fcb assumption; this time true"
       
   263   apply (induct_tac as rule: trm_assn.inducts(2))
       
   264   apply (rule TrueI)+
       
   265   apply (simp_all add: trm_assn.bn_defs fresh_star_def)[2]
       
   266   apply (auto simp add: Abs_fresh_iff)[1]
       
   267   apply assumption+
       
   268 --"But eqvt is not going to be true as well"
       
   269   apply (simp add: fresh_star_Pair_elim perm_supp_eq eqvt_at_def trm_assn.fv_bn_eqvt)
       
   270   apply (simp add: apply_assn_eqvt)
       
   271   apply (drule sym)
       
   272   apply (subgoal_tac "p \<bullet> (\<lambda>x2\<Colon>trm. subst_sumC (sa, ta, x2)) = (\<lambda>x2\<Colon>trm. subst_sumC (sa, ta, x2))")
       
   273   apply (simp)
       
   274   apply (erule alpha_bn_inducts)
       
   275   apply simp
       
   276   apply simp
       
   277   apply (simp add: trm_assn.bn_defs)
       
   278 --"Again we cannot relate 'namea' with 'p \<bullet> name'"
       
   279   prefer 4
       
   280   apply (erule alpha_bn_inducts)
       
   281   apply simp_all[2]
       
   282   oops
       
   283 
       
   284 end