lh-l4v/lib/BCorres_UL.thy

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(*
* Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
*
* SPDX-License-Identifier: BSD-2-Clause
*)
theory BCorres_UL
imports
Monads.NonDetMonadVCG
Crunch_Instances_NonDet
begin
definition s_bcorres_underlying where
"s_bcorres_underlying t f g s \<equiv> (\<lambda>(x,y). (x, t y)) ` (fst (f s)) \<subseteq> (fst (g (t s)))"
definition bcorres_underlying where
"bcorres_underlying t f g \<equiv> \<forall>s. s_bcorres_underlying t f g s"
lemma wpc_helper_bcorres:
"bcorres_underlying t f g \<Longrightarrow> wpc_helper P Q (bcorres_underlying t f g)"
by (simp add: wpc_helper_def split: prod.split)
lemma wpc_helper_s_bcorres:
"s_bcorres_underlying t f g s \<Longrightarrow> wpc_helper P Q (s_bcorres_underlying t f g s)"
by (simp add: wpc_helper_def split: prod.split)
wpc_setup "\<lambda>f. bcorres_underlying t f g" wpc_helper_bcorres
wpc_setup "\<lambda>f. s_bcorres_underlying t f g s" wpc_helper_bcorres
lemma s_bcorres_underlying_split[wp_split]:
"(\<And>r s'. (r,s') \<in> fst (f s) \<Longrightarrow> (s_bcorres_underlying t (g r) (g' r) s')) \<Longrightarrow>
s_bcorres_underlying t f f' s \<Longrightarrow>
s_bcorres_underlying t (f >>= g) (f' >>= g') s"
by (clarsimp simp: s_bcorres_underlying_def bind_def) force
lemma bcorres_underlying_split[wp_split]:
"(\<And>r. (bcorres_underlying t (g r) (g' r))) \<Longrightarrow>
bcorres_underlying t f f' \<Longrightarrow>
bcorres_underlying t (f >>= g) (f' >>= g')"
by (simp add: bcorres_underlying_def s_bcorres_underlying_split)
lemma get_s_bcorres_underlying[wp]:
"s_bcorres_underlying t (f s) (f' (t s)) s \<Longrightarrow> s_bcorres_underlying t (get >>= f) (get >>= f') s"
by (simp add: gets_def s_bcorres_underlying_def get_def bind_def return_def)
lemma get_bcorres[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' (t x))) \<Longrightarrow> bcorres_underlying t (get >>= f) (get >>= f')"
by (simp add: bcorres_underlying_def get_s_bcorres_underlying)
lemma gets_s_bcorres_underlying[wp]:
"x' (t s) = x s \<Longrightarrow> s_bcorres_underlying t (gets x) (gets x') s"
by (simp add: s_bcorres_underlying_def gets_def get_def bind_def return_def)
lemma gets_bcorres_underlying[wp]:
"(\<And>s. x' (t s) = x s) \<Longrightarrow> bcorres_underlying t (gets x) (gets x')"
by (simp add: bcorres_underlying_def gets_s_bcorres_underlying)
lemma gets_map_bcorres_underlying[wp]:
"(\<And>s. f' (t s) p = f s p) \<Longrightarrow> bcorres_underlying t (gets_map f p) (gets_map f' p)"
by (simp add: gets_map_def bcorres_underlying_def s_bcorres_underlying_def simpler_gets_def
bind_def assert_opt_def fail_def return_def
split: option.splits)
lemma gets_bcorres_underlying':
"(\<And>xa. bcorres_underlying t (f (x xa)) (f' (x' (t xa)))) \<Longrightarrow>
bcorres_underlying t (gets x >>= f) (gets x' >>= f')"
by (wpsimp simp: gets_def)
lemma assert_bcorres_underlying[wp]:
"f = f' \<Longrightarrow> bcorres_underlying t (assert f) (assert f')"
by (simp add: assert_def bcorres_underlying_def return_def s_bcorres_underlying_def fail_def)
lemma return_bcorres[wp]:
"bcorres_underlying t (return x) (return x)"
by (simp add:return_def bcorres_underlying_def s_bcorres_underlying_def)
lemma drop_sbcorres_underlying:
"bcorres_underlying t f g \<Longrightarrow> s_bcorres_underlying t f g s"
by (simp add: bcorres_underlying_def)
lemma use_sbcorres_underlying:
"(\<And>s. s_bcorres_underlying t f g s) \<Longrightarrow> bcorres_underlying t f g"
by (simp add: bcorres_underlying_def)
lemma bcorres_underlying_throwError[wp]:
"bcorres_underlying t (throwError a) (throwError a)"
by (wpsimp simp: throwError_def)
lemma s_bcorres_underlying_splitE[wp_split]:
"(\<And>r s'. (Inr r,s') \<in> fst (f s) \<Longrightarrow> s_bcorres_underlying t (g r) (g' r) s') \<Longrightarrow>
s_bcorres_underlying t f f' s \<Longrightarrow>
s_bcorres_underlying t (f >>=E g) (f' >>=E g') s"
by (wpsimp simp: bindE_def lift_def split: sum.splits | rule conjI drop_sbcorres_underlying)+
lemma get_s_bcorres_underlyingE[wp]:
"s_bcorres_underlying t (f s) (f' (t s)) s \<Longrightarrow>
s_bcorres_underlying t (liftE get >>=E f) (liftE get >>=E f') s"
by (simp add: gets_def s_bcorres_underlying_def get_def bindE_def bind_def return_def liftE_def lift_def)
lemma bcorres_underlying_splitE[wp_split]:
"(\<And>r. bcorres_underlying t (g r) (g' r)) \<Longrightarrow>
bcorres_underlying t f f' \<Longrightarrow>
bcorres_underlying t (f >>=E g) (f' >>=E g')"
by (simp add: bcorres_underlying_def s_bcorres_underlying_splitE)
lemmas return_s_bcorres_underlying[wp] = drop_sbcorres_underlying[OF return_bcorres]
lemma liftE_s_bcorres_underlying[wp]:
"s_bcorres_underlying t f f' s \<Longrightarrow> s_bcorres_underlying t (liftE f) (liftE f') s"
by (wpsimp simp: liftE_def)
lemma liftE_bcorres_underlying[wp]:
"bcorres_underlying t f f' \<Longrightarrow> bcorres_underlying t (liftE f) (liftE f')"
by (simp add: bcorres_underlying_def liftE_s_bcorres_underlying)
lemma returnOk_bcorres_underlying[wp]:
"bcorres_underlying t (returnOk x) (returnOk x)"
by (wpsimp simp: returnOk_def)
lemma whenE_s_bcorres_underlying[wp]:
"\<lbrakk> \<lbrakk>P = P'; P\<rbrakk> \<Longrightarrow> s_bcorres_underlying t f f' s; P = P' \<rbrakk> \<Longrightarrow>
s_bcorres_underlying t (whenE P f) (whenE P' f') s"
by (wpsimp simp: whenE_def|rule drop_sbcorres_underlying)+
lemma select_s_bcorres_underlying[wp]:
"A \<subseteq> B \<Longrightarrow> s_bcorres_underlying t (select A) (select B) s"
by (simp add: s_bcorres_underlying_def select_def image_def) blast
lemma fail_s_bcorres_underlying[wp]:
"s_bcorres_underlying t fail fail s"
by (simp add: s_bcorres_underlying_def fail_def)
lemma fail_bcorres_underlying[wp]:
"bcorres_underlying t fail fail"
by (simp add: bcorres_underlying_def fail_s_bcorres_underlying)
lemma assertE_bcorres_underlying[wp]:
"bcorres_underlying t (assertE P) (assertE P)"
by (wpsimp simp: assertE_def returnOk_def|rule conjI)+
lemmas assertE_s_bcorres_underlying[wp] = drop_sbcorres_underlying[OF assertE_bcorres_underlying]
lemma when_s_bcorres_underlying[wp]:
"(P \<Longrightarrow> s_bcorres_underlying t f f' s) \<Longrightarrow> s_bcorres_underlying t (when P f) (when P f') s"
by (simp add: return_s_bcorres_underlying when_def)
lemma when_bcorres_underlying[wp]:
"(P \<Longrightarrow> bcorres_underlying t f f') \<Longrightarrow> bcorres_underlying t (when P f) (when P f')"
by (simp add: bcorres_underlying_def when_s_bcorres_underlying)
lemma put_bcorres_underlying[wp]:
"t f = f' \<Longrightarrow> bcorres_underlying t (put f) (put f')"
by (simp add: bcorres_underlying_def s_bcorres_underlying_def put_def)
lemma modify_bcorres_underlying[wp]:
"(\<And>x. t (f x) = f' (t x)) \<Longrightarrow> bcorres_underlying t (modify f) (modify f')"
by (wpsimp simp: modify_def)
lemma liftM_bcorres_underlying[wp]:
"bcorres_underlying t m m' \<Longrightarrow> bcorres_underlying t (liftM f m) (liftM f m')"
by (wpsimp simp: liftM_def)
lemma sequence_x_bcorres_underlying[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow>
bcorres_underlying t (sequence_x (map f xs)) (sequence_x (map f' xs))"
by (induct xs; wpsimp simp: sequence_x_def)
lemma sequence_bcorres_underlying[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow>
bcorres_underlying t (sequence (map f xs)) (sequence (map f' xs))"
by (induct xs; wpsimp simp: sequence_def)
lemma mapM_x_bcorres_underlying[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow> bcorres_underlying t (mapM_x f xs) (mapM_x f' xs)"
by (wpsimp simp: mapM_x_def)
lemma mapM_bcorres_underlying[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow> bcorres_underlying t (mapM f xs) (mapM f' xs)"
by (simp add: mapM_def | wp)+
lemma gets_s_bcorres_underlyingE':
"s_bcorres_underlying t (f (x s)) (f' (x' (t s))) s \<Longrightarrow>
s_bcorres_underlying t (liftE (gets x) >>=E f) (liftE (gets x') >>=E f') s"
by (simp add: gets_def liftE_def lift_def bindE_def) wp
lemma bcorres_underlying_filterM[wp]:
"(\<And>x. bcorres_underlying t (a x) (a' x)) \<Longrightarrow> bcorres_underlying t (filterM a b) (filterM a' b)"
by (induct b; wpsimp simp: filterM_def)
lemma option_rec_bcorres_underlying[wp_split]:
"(\<And>x y. bcorres_underlying t (g x y) (g' x y)) \<Longrightarrow>
(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow>
bcorres_underlying t (rec_option f g a b) (rec_option f' g' a b)"
by (cases a, simp+)
lemma bcorres_underlying_mapME[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow> bcorres_underlying t (mapME f r) (mapME f' r)"
by (induct r; wpsimp simp: mapME_def sequenceE_def)
lemma handle2_bcorres_underlying[wp]:
"bcorres_underlying t f f' \<Longrightarrow>
(\<And>x. bcorres_underlying t (g x) (g' x)) \<Longrightarrow>
bcorres_underlying t (f <handle2> g) (f' <handle2> g')"
by (wpsimp simp: handleE'_def)
lemma liftME_bcorres_underlying[wp]:
"bcorres_underlying t f f' \<Longrightarrow> bcorres_underlying t (liftME a f) (liftME a f')"
by (wpsimp simp: liftME_def)
lemma zipWithM_x_bcorres[wp]:
"(\<And>x y. bcorres_underlying t (f x y) (f' x y) ) \<Longrightarrow>
bcorres_underlying t (zipWithM_x f xs ys) (zipWithM_x f' xs ys)"
by (wpsimp simp: zipWithM_x_def zipWith_def split_def)
lemma mapME_x_bcorres_underlying[wp]:
"(\<And>x. bcorres_underlying t (f x) (f' x)) \<Longrightarrow> bcorres_underlying t (mapME_x f xs) (mapME_x f' xs)"
by (induct xs; wpsimp simp: mapME_x_def sequenceE_x_def)
lemma liftE_bind_bcorres[wp]:
"bcorres_underlying t (f >>= g) (f' >>= g') \<Longrightarrow>
bcorres_underlying t (liftE f >>=E g) (liftE f' >>=E g')"
by (simp add: gets_def bcorres_underlying_def s_bcorres_underlying_def get_def bind_def return_def
split_def liftE_def bindE_def lift_def)
lemma select_f_bcorres[wp]: "bcorres_underlying t (select_f f) (select_f f)"
by (fastforce simp: select_f_def bcorres_underlying_def s_bcorres_underlying_def)
lemma bcorres_underlying_if[wp]:
"(b \<Longrightarrow> bcorres_underlying t f f') \<Longrightarrow>
(\<not>b \<Longrightarrow> bcorres_underlying t g g') \<Longrightarrow>
bcorres_underlying t (if b then f else g) (if b then f' else g')"
by (case_tac b; simp)
lemma assert_opt_bcorres_underlying[wp]:
"bcorres_underlying t (assert_opt f) (assert_opt f)"
by (wpsimp simp: assert_opt_def)
lemma unlessb_corres_underlying[wp]:
"bcorres_underlying t f f' \<Longrightarrow> bcorres_underlying t (unless a f) (unless a f')"
by (wpsimp simp: unless_def)
lemma select_bcorres_underlying[wp]:
"A \<subseteq> B \<Longrightarrow> bcorres_underlying t (select A) (select B)"
by (fastforce simp: bcorres_underlying_def select_def s_bcorres_underlying_def)
lemma catch_bcorres[wp]:
"bcorres_underlying t f f' \<Longrightarrow>
(\<And>x. bcorres_underlying t (g x) (g' x)) \<Longrightarrow>
bcorres_underlying t (f <catch> g) (f' <catch> g')"
unfolding catch_def by wpsimp
lemma whenE_bcorres_underlying[wp]:
"\<lbrakk> \<lbrakk>P = P'; P\<rbrakk> \<Longrightarrow> bcorres_underlying t f f'; P = P' \<rbrakk> \<Longrightarrow>
bcorres_underlying t (whenE P f) (whenE P' f')"
unfolding whenE_def by wpsimp
lemma unlessE_bcorres[wp]:
"bcorres_underlying t f f' \<Longrightarrow> bcorres_underlying t (unlessE P f) (unlessE P f')"
by (wpsimp simp: unlessE_def)
lemma alternative_bcorres[wp]:
"\<lbrakk> bcorres_underlying t f f'; bcorres_underlying t g g' \<rbrakk> \<Longrightarrow>
bcorres_underlying t (f \<sqinter> g) (f' \<sqinter> g')"
by (fastforce simp: alternative_def bcorres_underlying_def s_bcorres_underlying_def)
lemma gets_the_bcorres_underlying[wp]:
"(\<And>s. f' (t s) = f s) \<Longrightarrow> bcorres_underlying t (gets_the f) (gets_the f')"
by (wpsimp simp: gets_the_def)
ML \<open>
structure CrunchBCorresInstance : CrunchInstance =
struct
val name = "bcorres";
val prefix_name_scheme = false;
type extra = term;
val eq_extra = ae_conv;
fun parse_extra ctxt extra
= case extra of
"" => error "bcorres needs truncate function"
| e =>(Syntax.parse_term ctxt "%_. True", Syntax.parse_term ctxt e);
val has_preconds = false;
fun mk_term _ body extra =
(Syntax.parse_term @{context} "bcorres_underlying") $ extra $ body $ body;
fun dest_term (Const (@{const_name "bcorres_underlying"}, _) $ extra $ body $ _)
= SOME (Term.dummy, body, extra)
| dest_term _ = NONE;
fun put_precond _ ((v as Const (@{const_name "bcorres_underlying"}, _)) $ extra $ body $ body')
= v $ extra $ body $ body'
| put_precond _ _ = error "put_precond: not an bcorres term";
val pre_thms = [];
val wpc_tactic = WeakestPreCases.wp_cases_tac @{thms wpc_processors};
fun wps_tactic _ _ _ = no_tac;
val magic = Syntax.parse_term @{context}
"\<lambda>mapp_lambda_ignore. bcorres_underlying t_free_ignore mapp_lambda_ignore g_free_ignore";
val get_monad_state_type = get_nondet_monad_state_type;
end;
structure CrunchBCorres : CRUNCH = Crunch(CrunchBCorresInstance);
\<close>
setup \<open>
add_crunch_instance "bcorres" (CrunchBCorres.crunch_x, CrunchBCorres.crunch_ignore_add_dels)
\<close>
end