fact: Definition isofnelcompl {X : UU} {n : nat} (x : X) (sx : isofnel (S n) X) : isofnel n (compl X x) := hinhfun (nelstructoncompl x) sx.
imports: UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.NegativePropositions UniMath.Combinatorics.StandardFiniteSets UniMath.MoreFoundations.Subtypes