src/HOL/BNF/Tools/bnf_fp_rec_sugar_tactics.ML
author blanchet
Thu, 26 Sep 2013 02:09:52 +0200
changeset 55040 27fd72593624
parent 55039 396999552212
child 55041 446076262e92
permissions -rw-r--r--
more powerful/robust tactics
     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_tac: thm list -> thm list -> thm -> thm list -> tactic
    12   val mk_primcorec_code_of_ctr_tac: Proof.context -> thm list -> thm list -> thm list -> thm list ->
    13     thm list -> int list -> 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 split_if = @{thm split_if};
    29 val split_if_asm = @{thm split_if_asm};
    30 val split_connectI = @{thms allI impI conjI};
    31 
    32 fun mk_primrec_tac ctxt num_extra_args map_idents map_comps fun_defs recx =
    33   unfold_thms_tac ctxt fun_defs THEN
    34   HEADGOAL (rtac (funpow num_extra_args (fn thm => thm RS fun_cong) recx RS trans)) THEN
    35   unfold_thms_tac ctxt (@{thms id_def split o_def fst_conv snd_conv} @ map_comps @ map_idents) THEN
    36   HEADGOAL (rtac refl);
    37 
    38 fun mk_primcorec_assumption_tac ctxt discIs =
    39   HEADGOAL (SELECT_GOAL (unfold_thms_tac ctxt
    40       @{thms not_not not_False_eq_True de_Morgan_conj de_Morgan_disj} THEN
    41     SOLVE (HEADGOAL (REPEAT o (rtac refl ORELSE' atac ORELSE'
    42     resolve_tac @{thms TrueI conjI disjI1 disjI2} ORELSE'
    43     dresolve_tac discIs THEN' atac)))));
    44 
    45 fun mk_primcorec_same_case_tac m =
    46   HEADGOAL (if m = 0 then rtac TrueI
    47     else REPEAT_DETERM_N (m - 1) o (rtac conjI THEN' atac) THEN' atac);
    48 
    49 fun mk_primcorec_different_case_tac ctxt excl =
    50   unfold_thms_tac ctxt @{thms not_not not_False_eq_True} THEN
    51   HEADGOAL (rtac excl THEN_ALL_NEW SELECT_GOAL (mk_primcorec_assumption_tac ctxt []));
    52 
    53 fun mk_primcorec_cases_tac ctxt k m exclsss =
    54   let val n = length exclsss in
    55     EVERY (map (fn [] => if k = n then all_tac else mk_primcorec_same_case_tac m
    56         | [excl] => mk_primcorec_different_case_tac ctxt excl)
    57       (take k (nth exclsss (k - 1))))
    58   end;
    59 
    60 fun mk_primcorec_prelude ctxt defs thm =
    61   unfold_thms_tac ctxt defs THEN HEADGOAL (rtac thm) THEN unfold_thms_tac ctxt @{thms split};
    62 
    63 fun mk_primcorec_disc_tac ctxt defs disc_corec k m exclsss =
    64   mk_primcorec_prelude ctxt defs disc_corec THEN mk_primcorec_cases_tac ctxt k m exclsss;
    65 
    66 fun mk_primcorec_sel_tac ctxt defs f_sel k m exclsss maps map_idents map_comps splits split_asms =
    67   mk_primcorec_prelude ctxt defs (f_sel RS trans) THEN
    68   mk_primcorec_cases_tac ctxt k m exclsss THEN
    69   unfold_thms_tac ctxt (@{thms o_def split_def sum.cases} @ maps @ map_comps @ map_idents) THEN
    70   HEADGOAL (REPEAT_DETERM o (rtac refl ORELSE'
    71     eresolve_tac @{thms not_TrueE FalseE} ORELSE'
    72     resolve_tac split_connectI ORELSE'
    73     Splitter.split_asm_tac (split_if_asm :: split_asms) ORELSE'
    74     Splitter.split_tac (split_if :: splits) ORELSE'
    75     etac notE THEN' atac));
    76 
    77 fun mk_primcorec_ctr_of_dtr_tac ctxt m collapse maybe_disc_f sel_fs =
    78   HEADGOAL (rtac ((if null sel_fs then collapse else collapse RS sym) RS trans) THEN'
    79     (the_default (K all_tac) (Option.map rtac maybe_disc_f)) THEN' REPEAT_DETERM_N m o atac) THEN
    80   unfold_thms_tac ctxt sel_fs THEN HEADGOAL (rtac refl);
    81 
    82 fun mk_primcorec_split distincts discIs collapses splits split_asms =
    83   HEADGOAL (SELECT_GOAL (HEADGOAL (REPEAT_DETERM o (rtac refl ORELSE' atac ORELSE'
    84     eresolve_tac (@{thms not_TrueE FalseE} @ map (fn thm => thm RS trans) collapses) ORELSE'
    85     resolve_tac split_connectI ORELSE'
    86     Splitter.split_asm_tac (split_if_asm :: split_asms) ORELSE'
    87     Splitter.split_tac (split_if :: splits) ORELSE'
    88     eresolve_tac (map (fn thm => thm RS @{thm neq_eq_eq_contradict}) distincts) THEN' atac ORELSE'
    89     (TRY o dresolve_tac discIs) THEN' etac notE THEN' atac))));
    90 
    91 fun mk_primcorec_code_of_ctr_single_tac ctxt distincts discIs collapses splits split_asms m f_ctr =
    92   HEADGOAL (REPEAT o (resolve_tac split_connectI ORELSE' split_tac (split_if :: splits))) THEN
    93   mk_primcorec_prelude ctxt [] (f_ctr RS trans) THEN
    94   REPEAT_DETERM_N m (mk_primcorec_assumption_tac ctxt discIs) THEN
    95   mk_primcorec_split distincts discIs collapses splits split_asms;
    96 
    97 fun mk_primcorec_code_of_ctr_tac ctxt distincs discIs collapses splits split_asms ms ctr_thms =
    98   EVERY (map2 (mk_primcorec_code_of_ctr_single_tac ctxt distincs discIs collapses splits split_asms)
    99     ms ctr_thms);
   100 
   101 fun mk_primcorec_code_tac eq_caseIs disc_excludes raw collapses =
   102   HEADGOAL (rtac raw ORELSE' rtac (raw RS trans) THEN' REPEAT o
   103     (resolve_tac (maps (fn thm => [thm, thm RS sym]) (@{thm eq_ifI} :: eq_caseIs)) ORELSE'
   104      rtac refl ORELSE' etac notE THEN' atac ORELSE'
   105      dresolve_tac disc_excludes THEN' etac notE THEN' atac ORELSE'
   106      eresolve_tac (maps (fn thm => [thm, thm RS sym]) collapses)));
   107 
   108 end;