proposition: Lemma nImp (xm : XM) (P Q : Prop) : ~ (P -> Q) -> P /\ ~ Q.
proof: Proof. case: (xm P); tauto. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert) CompDecModal.CTL(CTL_def hilbert)