proposition: Lemma axARE s t : prv (fAR s t ---> t).
proof: Proof. rule ax_contra. rewrite -> axARdef, axDNE,axEUeq. exact: axOIl. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert) CompDecModal.CTL(CTL_def hilbert)