fact: Definition Ed (X : preZFS) : (Ve X) → (Ve X) → hProp := pr1 (pr2 (pr1 (pr1 X))).
imports: UniMath.Foundations.PartB UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.Foundations.HLevels UniMath.Combinatorics.WellOrderedSets UniMath.Combinatorics.OrderedSets UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.Propositions