lh-l4v/lib/sep_algebra/Sep_Cancel.thy

69 lines
2.7 KiB
Plaintext

(*
* Copyright 2014, NICTA
*
* This software may be distributed and modified according to the terms of
* the BSD 2-Clause license. Note that NO WARRANTY is provided.
* See "LICENSE_BSD2.txt" for details.
*
* @TAG(NICTA_BSD)
*)
theory Sep_Cancel
imports Sep_Provers Sep_Tactic_Helpers Sep_Cancel_Set
begin
(* Sep_Cancel performs cancellative elimination of conjuncts *)
lemma sep_curry': "\<lbrakk>(P \<and>* F) s; \<And>s. (Q \<and>* P \<and>* F) s \<Longrightarrow> R s\<rbrakk> \<Longrightarrow> (Q \<longrightarrow>* R) s"
by (metis (full_types) sep.mult_commute sep_curry)
lemma sep_conj_sep_impl_safe:
"(P \<longrightarrow>* P') s \<Longrightarrow> (\<And>s. ((P \<longrightarrow>* P') \<and>* Q) s \<Longrightarrow> (Q') s) \<Longrightarrow> (Q \<longrightarrow>* Q') s"
by (rule sep_curry)
lemma sep_conj_sep_impl_safe': "P s \<Longrightarrow> (\<And>s. (P \<and>* Q) s \<Longrightarrow> (P \<and>* R) s) \<Longrightarrow> (Q \<longrightarrow>* P \<and>* R) s"
by (rule sep_curry)
lemma sep_wand_lens_simple: "(\<And>s. T s = (Q \<and>* R) s) \<Longrightarrow> (P \<longrightarrow>* T) s \<Longrightarrow> (P \<longrightarrow>* Q \<and>* R) s"
by (clarsimp simp: sep_impl_def)
schematic_goal schem_impAny: " (?C \<and>* B) s \<Longrightarrow> A s" by (erule sep_mp)
ML \<open>
fun sep_cancel_tactic ctxt concl =
let val thms = rev (SepCancel_Rules.get ctxt)
val tac = assume_tac ctxt ORELSE'
eresolve_tac ctxt [@{thm sep_mp}, @{thm sep_conj_empty}, @{thm sep_empty_conj}] ORELSE'
sep_erule_tactic ctxt thms
val direct_tac = eresolve_tac ctxt thms
val safe_sep_wand_tac = rotator' ctxt (resolve0_tac [@{thm sep_wand_lens_simple}]) (eresolve0_tac [@{thm sep_conj_sep_impl_safe'}])
fun sep_cancel_tactic_inner true = sep_erule_full_tac' tac ctxt
| sep_cancel_tactic_inner false = sep_erule_full_tac tac ctxt
in sep_cancel_tactic_inner concl ORELSE'
eresolve_tac ctxt [@{thm sep_curry'}, @{thm sep_conj_sep_impl_safe}, @{thm sep_imp_empty}, @{thm sep_empty_imp'}] ORELSE'
safe_sep_wand_tac ORELSE'
direct_tac
end
fun sep_cancel_tactic' ctxt concl =
let
val sep_cancel = sep_cancel_tactic ctxt
in
(sep_flatten ctxt THEN_ALL_NEW sep_cancel concl) ORELSE' sep_cancel concl
end
fun sep_cancel_method (concl,_) ctxt = SIMPLE_METHOD' (sep_cancel_tactic' ctxt concl)
val sep_cancel_syntax =
Method.sections [Args.add -- Args.colon >> K (Method.modifier SepCancel_Rules.add @{here})];
val sep_cancel_syntax' =
Scan.lift (Args.mode "concl") -- sep_cancel_syntax
\<close>
method_setup sep_cancel =
\<open>sep_cancel_syntax' >> sep_cancel_method\<close> \<open>Simple elimination of conjuncts\<close>
end