fact: Definition base_default : (T → hProp) → hProp := λ P : T → hProp, isOpen P ∧ P x.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Topology.Filters UniMath.Algebra.Groups UniMath.Algebra.DivisionRig UniMath.Algebra.ConstructiveStructures