proposition: Lemma sub_sfc C : C `<=` (sfc C).
proof: Proof. rewrite /sfc. apply/subP => s inC. apply/cupP. exists s => //. by rewrite inC ssub_refl. Qed.
imports: Relations mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base modular_hilbert sltype)