proposition: Lemma truncminus_le_r : ∏ k x y : X, Lle lat x y → Lle lat (truncminus ex x k) (truncminus ex y k).
proof: Proof. intros k x y <-. eapply rcancel. { apply is1. } simpl. rewrite is3, 2!istruncminus_ex. rewrite is4, isassoc_Lmin, Lmin_id. rewrite <- is4. apply pathsinv0, istruncminus_ex. Qed.
imports: UniMath.MoreFoundations.All UniMath.Algebra.Monoids UniMath.Algebra.Groups