fact: Definition underlyingPoset_weq (X Y:OrderedSet) : X=Y ≃ (underlyingPoset X)=(underlyingPoset Y).
imports: UniMath.Combinatorics.FiniteSets UniMath.Foundations.UnivalenceAxiom UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions