fact: Definition continuous_at {U V : TopologicalSpace} (f : U → V) (x : U) := is_lim f (locally x) (f x).
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Topology.Filters UniMath.Algebra.Groups UniMath.Algebra.DivisionRig UniMath.Algebra.ConstructiveStructures