fact: Definition upto {X:hSet} {S:WOSubset X} (s:S) : hsubtype X := (λ x, ∑ h:S x, (x,,h) < s)%prop.
imports: UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.Propositions UniMath.MoreFoundations.Subtypes UniMath.MoreFoundations.Sets UniMath.MoreFoundations.AxiomOfChoice UniMath.Combinatorics.OrderedSets