fact: Definition OrderedSet_isantisymm {X:OrderedSet} (x y:X) : x ≤ y -> y ≤ x -> x = y.
imports: UniMath.Combinatorics.FiniteSets UniMath.Foundations.UnivalenceAxiom UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions