proposition: Lemma sf_AU s t b : ((fAU s t,b) \in F) = ((fAX (fAU s t),b) \in F).
proof: Proof. apply/idP/idP; move/sfc_F => //=. by bcase. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base sltype) CompDecModal.CTL(CTL_def gen_def)