proposition: Lemma locally_base_imply : isfilter_imply (neighborhood' x base).
proof: Proof. intros A B H Ha. apply (pr2 (neighborhood_equiv _ _ _)). eapply neighborhood_imply. - exact H. - eapply neighborhood_equiv. exact Ha. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Topology.Filters UniMath.Algebra.Groups UniMath.Algebra.DivisionRig UniMath.Algebra.ConstructiveStructures