Definition semax vars (G: funspecs) (P: assert) (k: control) : Prop :=
typecheck vars k = true /\ forall n,  semax' (SemaxArg vars (fun s => P s && funassert G) k) n.
Definition semax_func (G: funspecs) (p: program) (G': funspecs) :=
match_specs p G' /\
forall n, believe_all semax' G p G' n.

Lemma semax_store: forall x y v c vars G (P: assert),
expcheck vars x = true ->
expcheck vars y = true ->
semax vars G (fun s => mapsto (eval x s) (eval y s) * P s) c ->
semax vars G (fun s => mapsto (eval x s) v  * P s)  (Do Mem x  := y ; c).