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