proposition: Lemma connected_component_sub A x : connected_component A x `<=` A.
proof: Proof. by move=> y [B [_ + _]] => /[apply]. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed