Fixpoint nat_dist_plus m n : nat_dist (m + n) m = n. Proof. revert m n; intros [|m'] ?. { simpl. apply nat_dist_m0. } { simpl. apply nat_dist_plus. } Defined.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.PartA.