Lemma isdecincldni ( n : nat ) ( i : ⟦S n⟧ ) : isdecincl ( dni i ). Proof. intros. intro j. induction ( stn_eq_or_neq i j ) as [eq|ne]. - induction eq. apply ( isdecpropfromneg ( neghfiberdni n i ) ). - exact ( isdecpropfromiscontr (iscontrhfiberdni _ _ _ ne) ). Defined.
Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions. Require Import UniMath.MoreFoundations.NegativePropositions.