Section chobjscIsSecure.
intros s t Sub FP6 SS TF; inversion TF.
inversion H.
unfold SecureState in |- *.
BreakSS.
split.
auto.
unfold MACSecureState in |- *; simpl in |- *; intros.
elim (OBJeq_dec o o0).
intro.
rewrite <- a.
cut (fsecmat (secmat s) o = None).
intro.
rewrite H6.
elim (fOSC (objectSC s) o); elim (fOSC (chobjsc_SC s o sc) o);
elim (fSSC (subjectSC s) u); contradiction || auto.
unfold fsecmat in |- *; auto.
intro.
replace (fOSC (chobjsc_SC s o sc) o0) with (fOSC (objectSC s) o0).
unfold MACSecureState in MAC; apply MAC.
auto.
Qed.

Lemma ChobjscPSP :
forall (s t : SFSstate) (u : SUBJECT),
FuncPre6 s -> StarProperty s -> TransFunc u s Chobjsc t -> StarProperty t.