intros until m; unfold fsecmat, open_sm in |- *.
elim m; elim (fsecmat (secmat s) o1).
intros; apply AddRemEq; auto.
intros; apply AddEq; auto.
intros; apply AddRemEq; auto.
intros; apply AddEq; auto.
Qed.

Lemma Chobjsc_Corr :
forall (s : SFSstate) (o : OBJECT) (sc : SecClass),
FuncPre6 s ->
(fOSC (objectSC s) o = None <-> fOSC (chobjsc_SC s o sc) o = None).