Section SOUNDNESS.
Variable bc: block_classification.
Variable ge: genv.
Hypothesis GENV: genv_match bc ge.
Variable sp: block.
Hypothesis STACK: bc sp = BCstack.
Ltac InvHyps :=
match goal with
| [H: None = Some _ |- _ ] => discriminate
| [H: Some _ = Some _ |- _] => inv H
| [H1: match ?vl with nil => _ | _ :: _ => _ end = Some _ ,
H2: list_forall2 _ ?vl _ |- _ ] => inv H2; InvHyps
| _ => idtac
end.

Lemma eval_static_extend_sound: forall v av x n,
vmatch bc v av -> vmatch bc (eval_extend x v n) (eval_static_extend x av n).