proposition: Lemma connected_component_out A x : ~ A x -> connected_component A x = set0.
proof: Proof. by move=> NAx; rewrite -subset0 => y [B [/[swap]/[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