fact: Definition weqdnicoprod_invmap {n : nat} (j : ⟦S n⟧ ) : ⟦n⟧ ⨿ unit <- ⟦S n⟧.
imports: UniMath.Foundations.NaturalNumbers UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.NegativePropositions