proposition: Lemma compact_openK_openE_subproof : compact_open_of_nbhs = [set A | A `<=` compact_openK_nbhs^~ A].
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed