proposition: Lemma genU_foc' s t C : (fAR s t^- |` C, aVoid) \in U -> (C, aAR (s, t, fset0)) \in U.
proof: Proof. by rewrite -AR_shift in_fsetX AsV [_ \in Hs]powersetE sub0x. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base sltype) CompDecModal.CTL(CTL_def gen_def)