proposition: Lemma prf_ref_sound C : prv ([af C] ---> Bot) -> ~ (exists M : fmodel, sat M C).
proof: Proof. move => H [M] [w] X. apply satA in X. exact: finite_soundness H M w X. Qed.
imports: Relations Lia mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert sltype) CompDecModal.Kstar(Kstar_def demo)