elim H; intros.
rewrite H0; rewrite H1.
auto.
Qed.

Lemma NotInDOMIsUndef2 :
forall (s : SFSstate) (o1 o2 : OBJECT),
~ set_In o1 (domsecmat (secmat s)) ->
o1 = o2 -> None = fsecmat (secmat s) o2.