proposition: Lemma axABBA s t : prv (fAX s :/\: fAX t ---> fAX (s :/\: t)).
proof: Proof. rewrite -> (axAXdef s),(axAXdef t),(axAXdef (s :/\: t)). rewrite <- dmO. rule ax_contraNN. rewrite <- axEXD. apply: rRegEX. rewrite -> dmA. exact: axI. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert) CompDecModal.CTL(CTL_def hilbert)