fact: Definition lexicographicOrder (X:hSet) (Y:X->hSet) (R:hrel X) (S : ∏ x, hrel (Y x)) : hrel (∑ x, Y x)%set.
imports: UniMath.Combinatorics.FiniteSets UniMath.Foundations.UnivalenceAxiom UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions