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