fact: Definition Hereditary_Lindelof_degree (X : TopologicalSpace) {Y : Type} (kappa : Ensemble Y) : Prop := least_cardinal (fun Y U => forall A : Ensemble X, Lindelof_degree_candidate (SubspaceTopology A) U) kappa.
imports: Coq(ClassicalChoice Description Program.Subset) ZornsLemma(Classical_Wf DecidableDec FiniteIntersections InfiniteTypes) Coq(RelationClasses)