Nominal/Ex/LetRecB.thy
changeset 2915 b4bf3ff4bc91
child 2916 b55098314f83
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2914:db0786a521fd 2915:b4bf3ff4bc91
       
     1 theory LetRecB
       
     2 imports "../Nominal2"
       
     3 begin
       
     4 
       
     5 atom_decl name
       
     6 
       
     7 nominal_datatype let_rec:
       
     8  trm =
       
     9   Var "name"
       
    10 | App "trm" "trm"
       
    11 | Lam x::"name" t::"trm"     bind x in t
       
    12 | Let_Rec bp::"bp" t::"trm"  bind "bn bp" in bp t
       
    13 and bp =
       
    14   Bp "name" "trm"
       
    15 binder
       
    16   bn::"bp \<Rightarrow> atom list"
       
    17 where
       
    18   "bn (Bp x t) = [atom x]"
       
    19 
       
    20 thm let_rec.distinct
       
    21 thm let_rec.induct
       
    22 thm let_rec.exhaust
       
    23 thm let_rec.fv_defs
       
    24 thm let_rec.bn_defs
       
    25 thm let_rec.perm_simps
       
    26 thm let_rec.eq_iff
       
    27 thm let_rec.fv_bn_eqvt
       
    28 thm let_rec.size_eqvt
       
    29 
       
    30 
       
    31 lemma Abs_lst_fcb2:
       
    32   fixes as bs :: "atom list"
       
    33     and x y :: "'b :: fs"
       
    34     and c::"'c::fs"
       
    35   assumes eq: "[as]lst. x = [bs]lst. y"
       
    36   and fcb1: "(set as) \<sharp>* f as x c"
       
    37   and fresh1: "set as \<sharp>* c"
       
    38   and fresh2: "set bs \<sharp>* c"
       
    39   and perm1: "\<And>p. supp p \<sharp>* c \<Longrightarrow> p \<bullet> (f as x c) = f (p \<bullet> as) (p \<bullet> x) c"
       
    40   and perm2: "\<And>p. supp p \<sharp>* c \<Longrightarrow> p \<bullet> (f bs y c) = f (p \<bullet> bs) (p \<bullet> y) c"
       
    41   shows "f as x c = f bs y c"
       
    42 proof -
       
    43   have "supp (as, x, c) supports (f as x c)"
       
    44     unfolding  supports_def fresh_def[symmetric]
       
    45     by (simp add: fresh_Pair perm1 fresh_star_def supp_swap swap_fresh_fresh)
       
    46   then have fin1: "finite (supp (f as x c))"
       
    47     by (auto intro: supports_finite simp add: finite_supp)
       
    48   have "supp (bs, y, c) supports (f bs y c)"
       
    49     unfolding  supports_def fresh_def[symmetric]
       
    50     by (simp add: fresh_Pair perm2 fresh_star_def supp_swap swap_fresh_fresh)
       
    51   then have fin2: "finite (supp (f bs y c))"
       
    52     by (auto intro: supports_finite simp add: finite_supp)
       
    53   obtain q::"perm" where 
       
    54     fr1: "(q \<bullet> (set as)) \<sharp>* (x, c, f as x c, f bs y c)" and 
       
    55     fr2: "supp q \<sharp>* Abs_lst as x" and 
       
    56     inc: "supp q \<subseteq> (set as) \<union> q \<bullet> (set as)"
       
    57     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"]  
       
    58       fin1 fin2
       
    59     by (auto simp add: supp_Pair finite_supp Abs_fresh_star dest: fresh_star_supp_conv)
       
    60   have "Abs_lst (q \<bullet> as) (q \<bullet> x) = q \<bullet> Abs_lst as x" by simp
       
    61   also have "\<dots> = Abs_lst as x"
       
    62     by (simp only: fr2 perm_supp_eq)
       
    63   finally have "Abs_lst (q \<bullet> as) (q \<bullet> x) = Abs_lst bs y" using eq by simp
       
    64   then obtain r::perm where 
       
    65     qq1: "q \<bullet> x = r \<bullet> y" and 
       
    66     qq2: "q \<bullet> as = r \<bullet> bs" and 
       
    67     qq3: "supp r \<subseteq> (q \<bullet> (set as)) \<union> set bs"
       
    68     apply(drule_tac sym)
       
    69     apply(simp only: Abs_eq_iff2 alphas)
       
    70     apply(erule exE)
       
    71     apply(erule conjE)+
       
    72     apply(drule_tac x="p" in meta_spec)
       
    73     apply(simp add: set_eqvt)
       
    74     apply(blast)
       
    75     done
       
    76   have "(set as) \<sharp>* f as x c" by (rule fcb1)
       
    77   then have "q \<bullet> ((set as) \<sharp>* f as x c)"
       
    78     by (simp add: permute_bool_def)
       
    79   then have "set (q \<bullet> as) \<sharp>* f (q \<bullet> as) (q \<bullet> x) c"
       
    80     apply(simp add: fresh_star_eqvt set_eqvt)
       
    81     apply(subst (asm) perm1)
       
    82     using inc fresh1 fr1
       
    83     apply(auto simp add: fresh_star_def fresh_Pair)
       
    84     done
       
    85   then have "set (r \<bullet> bs) \<sharp>* f (r \<bullet> bs) (r \<bullet> y) c" using qq1 qq2 by simp
       
    86   then have "r \<bullet> ((set bs) \<sharp>* f bs y c)"
       
    87     apply(simp add: fresh_star_eqvt set_eqvt)
       
    88     apply(subst (asm) perm2[symmetric])
       
    89     using qq3 fresh2 fr1
       
    90     apply(auto simp add: set_eqvt fresh_star_def fresh_Pair)
       
    91     done
       
    92   then have fcb2: "(set bs) \<sharp>* f bs y c" by (simp add: permute_bool_def)
       
    93   have "f as x c = q \<bullet> (f as x c)"
       
    94     apply(rule perm_supp_eq[symmetric])
       
    95     using inc fcb1 fr1 by (auto simp add: fresh_star_def)
       
    96   also have "\<dots> = f (q \<bullet> as) (q \<bullet> x) c" 
       
    97     apply(rule perm1)
       
    98     using inc fresh1 fr1 by (auto simp add: fresh_star_def)
       
    99   also have "\<dots> = f (r \<bullet> bs) (r \<bullet> y) c" using qq1 qq2 by simp
       
   100   also have "\<dots> = r \<bullet> (f bs y c)"
       
   101     apply(rule perm2[symmetric])
       
   102     using qq3 fresh2 fr1 by (auto simp add: fresh_star_def)
       
   103   also have "... = f bs y c"
       
   104     apply(rule perm_supp_eq)
       
   105     using qq3 fr1 fcb2 by (auto simp add: fresh_star_def)
       
   106   finally show ?thesis by simp
       
   107 qed
       
   108 
       
   109 
       
   110 lemma max_eqvt[eqvt]: "p \<bullet> (max (a :: _ :: pure) b) = max (p \<bullet> a) (p \<bullet> b)"
       
   111   by (simp add: permute_pure)
       
   112 
       
   113 nominal_primrec
       
   114     height_trm :: "trm \<Rightarrow> nat"
       
   115 and height_bp :: "bp \<Rightarrow> nat"
       
   116 where
       
   117   "height_trm (Var x) = 1"
       
   118 | "height_trm (App l r) = max (height_trm l) (height_trm r)"
       
   119 | "height_trm (Lam v b) = 1 + (height_trm b)"
       
   120 | "height_trm (Let_Rec bp b) = max (height_bp bp) (height_trm b)"
       
   121 | "height_bp (Bp v t) = height_trm t"
       
   122   --"eqvt"
       
   123   apply (simp only: eqvt_def height_trm_height_bp_graph_def)
       
   124   apply (rule, perm_simp, rule, rule TrueI)
       
   125   --"completeness"
       
   126   apply (case_tac x)
       
   127   apply (case_tac a rule: let_rec.exhaust(1))
       
   128   apply (auto)[4]
       
   129   apply (case_tac b rule: let_rec.exhaust(2))
       
   130   apply blast
       
   131   apply(simp_all)
       
   132   apply (erule_tac c="()" in Abs_lst_fcb2)
       
   133   apply (simp_all add: fresh_star_def pure_fresh)[3]
       
   134   apply (simp add: eqvt_at_def)
       
   135   apply (simp add: eqvt_at_def)
       
   136   --"HERE"
       
   137   thm  Abs_lst_fcb2
       
   138   apply(rule Abs_lst_fcb2)
       
   139      --" does not fit the assumption "
       
   140 
       
   141   apply (drule_tac c="()" in Abs_lst_fcb2)
       
   142   prefer 6
       
   143   apply(assumption)
       
   144   apply (drule_tac c="()" in Abs_lst_fcb2)
       
   145   apply (simp add: Abs_eq_iff2)
       
   146   apply (simp add: alphas)
       
   147   apply clarify
       
   148   apply (rule trans)
       
   149   apply(rule_tac p="p" in supp_perm_eq[symmetric])
       
   150   apply (simp add: pure_supp fresh_star_def)
       
   151   apply (simp only: eqvts)
       
   152   apply (simp add: eqvt_at_def)
       
   153   done
       
   154 
       
   155 termination by lexicographic_order
       
   156 
       
   157 end
       
   158 
       
   159 
       
   160