proposition: Corollary gen_correctness C : gen (C,aVoid) <-> ~ (exists M : cmodel, sat M C).
proof: Proof. split; first exact: gen_plain_sound. case: (gen_completeness C) => // [[M MC] H]. exfalso. apply H. by exists M. Qed.
imports: Relations Lia mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert sltype) CompDecModal.Kstar(Kstar_def demo hilbert_ref gen_def)