proposition: Lemma open_nbhsT (p : T) : open_nbhs p setT.
proof: Proof. by split=> //; apply: openT. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed