1 (* Title: HOL/BNF/Tools/bnf_fp_rec_sugar_tactics.ML
2 Author: Jasmin Blanchette, TU Muenchen
5 Tactics for recursor and corecursor sugar.
8 signature BNF_FP_REC_SUGAR_TACTICS =
10 val mk_primcorec_code_tac: Proof.context -> thm -> thm list -> tactic
11 val mk_primcorec_code_of_ctr_tac: Proof.context -> int list -> thm list -> tactic
12 val mk_primcorec_ctr_of_dtr_tac: Proof.context -> int -> thm -> thm -> thm list -> tactic
13 val mk_primcorec_ctr_or_sel_tac: Proof.context -> thm list -> thm -> int -> int ->
14 thm list list list -> thm list -> thm list -> thm list -> tactic
15 val mk_primcorec_disc_tac: Proof.context -> thm list -> thm -> int -> int -> thm list list list ->
17 val mk_primcorec_assumption_tac: Proof.context -> tactic
18 val mk_primrec_tac: Proof.context -> int -> thm list -> thm list -> thm list -> thm -> tactic
21 structure BNF_FP_Rec_Sugar_Tactics : BNF_FP_REC_SUGAR_TACTICS =
27 fun mk_primrec_tac ctxt num_extra_args map_idents map_comps fun_defs recx =
28 unfold_thms_tac ctxt fun_defs THEN
29 HEADGOAL (rtac (funpow num_extra_args (fn thm => thm RS fun_cong) recx RS trans)) THEN
30 unfold_thms_tac ctxt (@{thms id_def split o_def fst_conv snd_conv} @ map_comps @ map_idents) THEN
33 fun mk_primcorec_assumption_tac ctxt =
34 HEADGOAL (blast_tac (put_claset (claset_of @{theory_context HOL}) ctxt));
36 fun mk_primcorec_same_case_tac m =
37 HEADGOAL (if m = 0 then rtac TrueI
38 else REPEAT_DETERM_N (m - 1) o (rtac conjI THEN' atac) THEN' atac);
40 fun mk_primcorec_different_case_tac ctxt excl =
41 unfold_thms_tac ctxt @{thms not_not not_False_eq_True} THEN
42 HEADGOAL (rtac excl THEN_ALL_NEW SELECT_GOAL (mk_primcorec_assumption_tac ctxt));
44 fun mk_primcorec_cases_tac ctxt k m exclsss =
45 let val n = length exclsss in
46 EVERY (map (fn [] => if k = n then all_tac else mk_primcorec_same_case_tac m
47 | [excl] => mk_primcorec_different_case_tac ctxt excl)
48 (take k (nth exclsss (k - 1))))
51 fun mk_primcorec_prelude ctxt defs thm =
52 unfold_thms_tac ctxt defs THEN HEADGOAL (rtac thm) THEN unfold_thms_tac ctxt @{thms split};
54 fun mk_primcorec_disc_tac ctxt defs disc k m exclsss =
55 mk_primcorec_prelude ctxt defs disc THEN mk_primcorec_cases_tac ctxt k m exclsss;
57 fun mk_primcorec_ctr_or_sel_tac ctxt defs eq_thm k m exclsss maps map_idents map_comps =
58 mk_primcorec_prelude ctxt defs (eq_thm RS trans) THEN
59 mk_primcorec_cases_tac ctxt k m exclsss THEN
60 unfold_thms_tac ctxt (@{thms if_if_True if_if_False if_True if_False if_cancel[of _ True]
61 if_cancel[of _ False] o_def split_def sum.cases} @ maps @ map_comps @ map_idents) THEN
64 fun mk_primcorec_ctr_of_dtr_tac ctxt m collapse disc sels =
65 HEADGOAL (rtac (collapse RS sym RS trans) THEN' rtac disc THEN' REPEAT_DETERM_N m o atac) THEN
66 unfold_thms_tac ctxt sels THEN HEADGOAL (rtac refl);
68 fun mk_primcorec_code_of_ctr_case_tac ctxt m ctr_thm =
69 HEADGOAL (REPEAT o rtac @{thm eq_ifI}) THEN
70 mk_primcorec_prelude ctxt [] (ctr_thm RS trans) THEN
71 REPEAT_DETERM_N m (mk_primcorec_assumption_tac ctxt) THEN
72 HEADGOAL (asm_simp_tac (ss_only @{thms if_True if_False not_False_eq_True} ctxt));
74 fun mk_primcorec_code_of_ctr_tac ctxt ms ctr_thms =
75 EVERY (map2 (mk_primcorec_code_of_ctr_case_tac ctxt) ms ctr_thms);
77 fun mk_primcorec_code_tac ctxt raw collapses =
78 HEADGOAL (rtac (raw RS trans)) THEN unfold_thms_tac ctxt @{thms split_ifs} THEN
79 Method.intros_tac @{thms conjI impI} [] THEN
80 REPEAT (HEADGOAL (rtac refl ORELSE' (etac notE THEN' atac) ORELSE'
81 eresolve_tac (maps (fn thm => [thm, thm RS sym]) collapses)));