Section CENV_SUB.
intros.
rewrite <- (@eval_expr_cenv_sub_eq _ _ CSUB rho e); auto; congruence.
Qed.

Lemma eval_expr_cenv_sub_Vptr {CS CS'} (CSUB: cenv_sub (@cenv_cs CS) (@cenv_cs CS')) rho: forall e b i,
@eval_expr CS e rho = Vptr b i -> @eval_expr CS' e rho = Vptr b i.