src/HOL/BNF/Tools/bnf_fp_rec_sugar_tactics.ML
author blanchet
Thu, 26 Sep 2013 02:34:34 +0200
changeset 55042 158609f78d0f
parent 55041 446076262e92
child 55045 54afdc258272
permissions -rw-r--r--
tuning
     1 (*  Title:      HOL/BNF/Tools/bnf_fp_rec_sugar_tactics.ML
     2     Author:     Jasmin Blanchette, TU Muenchen
     3     Copyright   2013
     4 
     5 Tactics for recursor and corecursor sugar.
     6 *)
     7 
     8 signature BNF_FP_REC_SUGAR_TACTICS =
     9 sig
    10   val mk_primcorec_assumption_tac: Proof.context -> thm list -> tactic
    11   val mk_primcorec_code_of_ctr_tac: Proof.context -> thm list -> thm list -> thm list -> thm list ->
    12     thm list -> int list -> thm list -> tactic
    13   val mk_primcorec_code_of_raw_tac: thm list -> thm list -> thm -> thm list -> tactic
    14   val mk_primcorec_ctr_of_dtr_tac: Proof.context -> int -> thm -> thm option -> thm list -> tactic
    15   val mk_primcorec_disc_tac: Proof.context -> thm list -> thm -> int -> int -> thm list list list ->
    16     tactic
    17   val mk_primcorec_sel_tac: Proof.context -> thm list -> thm -> int -> int ->
    18     thm list list list -> thm list -> thm list -> thm list -> thm list -> thm list ->tactic
    19   val mk_primrec_tac: Proof.context -> int -> thm list -> thm list -> thm list -> thm -> tactic
    20 end;
    21 
    22 structure BNF_FP_Rec_Sugar_Tactics : BNF_FP_REC_SUGAR_TACTICS =
    23 struct
    24 
    25 open BNF_Util
    26 open BNF_Tactics
    27 
    28 val falseEs = @{thms not_TrueE FalseE};
    29 val split_if = @{thm split_if};
    30 val split_if_asm = @{thm split_if_asm};
    31 val split_connectI = @{thms allI impI conjI};
    32 
    33 fun mk_primrec_tac ctxt num_extra_args map_idents map_comps fun_defs recx =
    34   unfold_thms_tac ctxt fun_defs THEN
    35   HEADGOAL (rtac (funpow num_extra_args (fn thm => thm RS fun_cong) recx RS trans)) THEN
    36   unfold_thms_tac ctxt (@{thms id_def split o_def fst_conv snd_conv} @ map_comps @ map_idents) THEN
    37   HEADGOAL (rtac refl);
    38 
    39 fun mk_primcorec_assumption_tac ctxt discIs =
    40   HEADGOAL (SELECT_GOAL (unfold_thms_tac ctxt
    41       @{thms not_not not_False_eq_True de_Morgan_conj de_Morgan_disj} THEN
    42     SOLVE (HEADGOAL (REPEAT o (rtac refl ORELSE' atac ORELSE'
    43     resolve_tac @{thms TrueI conjI disjI1 disjI2} ORELSE'
    44     dresolve_tac discIs THEN' atac)))));
    45 
    46 fun mk_primcorec_same_case_tac m =
    47   HEADGOAL (if m = 0 then rtac TrueI
    48     else REPEAT_DETERM_N (m - 1) o (rtac conjI THEN' atac) THEN' atac);
    49 
    50 fun mk_primcorec_different_case_tac ctxt excl =
    51   unfold_thms_tac ctxt @{thms not_not not_False_eq_True} THEN
    52   HEADGOAL (rtac excl THEN_ALL_NEW SELECT_GOAL (mk_primcorec_assumption_tac ctxt []));
    53 
    54 fun mk_primcorec_cases_tac ctxt k m exclsss =
    55   let val n = length exclsss in
    56     EVERY (map (fn [] => if k = n then all_tac else mk_primcorec_same_case_tac m
    57         | [excl] => mk_primcorec_different_case_tac ctxt excl)
    58       (take k (nth exclsss (k - 1))))
    59   end;
    60 
    61 fun mk_primcorec_prelude ctxt defs thm =
    62   unfold_thms_tac ctxt defs THEN HEADGOAL (rtac thm) THEN unfold_thms_tac ctxt @{thms split};
    63 
    64 fun mk_primcorec_disc_tac ctxt defs disc_corec k m exclsss =
    65   mk_primcorec_prelude ctxt defs disc_corec THEN mk_primcorec_cases_tac ctxt k m exclsss;
    66 
    67 fun mk_primcorec_sel_tac ctxt defs f_sel k m exclsss maps map_idents map_comps splits split_asms =
    68   mk_primcorec_prelude ctxt defs (f_sel RS trans) THEN
    69   mk_primcorec_cases_tac ctxt k m exclsss THEN
    70   unfold_thms_tac ctxt (@{thms o_def split_def sum.cases} @ maps @ map_comps @ map_idents) THEN
    71   HEADGOAL (REPEAT_DETERM o (rtac refl ORELSE'
    72     eresolve_tac falseEs ORELSE'
    73     resolve_tac split_connectI ORELSE'
    74     Splitter.split_asm_tac (split_if_asm :: split_asms) ORELSE'
    75     Splitter.split_tac (split_if :: splits) ORELSE'
    76     etac notE THEN' atac));
    77 
    78 fun mk_primcorec_ctr_of_dtr_tac ctxt m collapse maybe_disc_f sel_fs =
    79   HEADGOAL (rtac ((if null sel_fs then collapse else collapse RS sym) RS trans) THEN'
    80     (the_default (K all_tac) (Option.map rtac maybe_disc_f)) THEN' REPEAT_DETERM_N m o atac) THEN
    81   unfold_thms_tac ctxt sel_fs THEN HEADGOAL (rtac refl);
    82 
    83 fun mk_primcorec_code_of_ctr_single_tac ctxt distincts discIs collapses splits split_asms m f_ctr =
    84   HEADGOAL (REPEAT o (resolve_tac split_connectI ORELSE' split_tac (split_if :: splits))) THEN
    85   mk_primcorec_prelude ctxt [] (f_ctr RS trans) THEN
    86   REPEAT_DETERM_N m (mk_primcorec_assumption_tac ctxt discIs) THEN
    87   HEADGOAL (SELECT_GOAL (HEADGOAL (REPEAT_DETERM o
    88     (rtac refl ORELSE' atac ORELSE'
    89      eresolve_tac (falseEs @ map (fn thm => thm RS trans) collapses) ORELSE'
    90      resolve_tac split_connectI ORELSE'
    91      Splitter.split_asm_tac (split_if_asm :: split_asms) ORELSE'
    92      Splitter.split_tac (split_if :: splits) ORELSE'
    93      eresolve_tac (map (fn thm => thm RS @{thm neq_eq_eq_contradict}) distincts) THEN' atac ORELSE'
    94      (TRY o dresolve_tac discIs) THEN' etac notE THEN' atac))));
    95 
    96 fun mk_primcorec_code_of_ctr_tac ctxt distincts discIs collapses splits split_asms ms ctr_thms =
    97   EVERY (map2 (mk_primcorec_code_of_ctr_single_tac ctxt distincts discIs collapses splits
    98     split_asms) ms ctr_thms);
    99 
   100 fun mk_primcorec_code_of_raw_tac splits disc_excludes raw collapses =
   101   HEADGOAL (rtac raw ORELSE' rtac (raw RS trans) THEN' REPEAT_DETERM o
   102     (rtac refl ORELSE'
   103      (TRY o rtac sym) THEN' atac ORELSE'
   104      resolve_tac split_connectI ORELSE'
   105      Splitter.split_tac (split_if :: splits) ORELSE'
   106      etac notE THEN' atac ORELSE'
   107      dresolve_tac disc_excludes THEN' etac notE THEN' atac ORELSE'
   108      eresolve_tac (maps (fn thm => [thm, thm RS sym]) collapses)));
   109 
   110 end;