proposition: Lemma axARu s t : prv (fAR s t ---> ~~: s ---> fAX (fAR s t)).
proof: Proof. rewrite -> axARf at 1. rule axAcase. by drop. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert) CompDecModal.CTL(CTL_def hilbert hilbert_hist)