Require Export VST.veric.environ_lemmas.
Require Export VST.veric.expr_lemmas3.
Require Export VST.veric.expr_lemmas4.
intros. unfold Map.set. unfold make_tenv. extensionality. rewrite PTree.gsspec; auto.
Qed.

Lemma cast_exists : forall {CS: compspecs} Delta e2 t rho phi
(TC: typecheck_environ Delta rho),
denote_tc_assert (typecheck_expr Delta e2) rho phi ->
denote_tc_assert (isCastResultType (typeof e2) t e2)
rho phi ->
sem_cast (typeof e2) t (eval_expr e2 rho)  =
Some (force_val (sem_cast (typeof e2) t (eval_expr e2 rho))).