proposition: Lemma meets_openl {T : topologicalType} (F : set_system T) (x : T) : nbhs x `#` F = open_nbhs x `#` F.
proof: Proof. by rewrite meetsC meets_openr meetsC. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed