proposition: Lemma axAUeq s t : prv (fAU s t <--> t :\/: (s :/\: fAX (fAU s t))).
proof: Proof. exact: axAUeq'. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert) CompDecModal.CTL(CTL_def hilbert)