proposition: Lemma minusleh ( n m : nat ) : natleh ( sub n m ) n.
proof: Proof. revert m. induction n. - intros m. apply isreflnatleh. - intros m. destruct m. + apply isreflnatleh. + apply ( istransnatleh (IHn m)). apply natlthtoleh. apply natlthnsn. Defined.
imports: UniMath.Tactics.EnsureStructuredProofs UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.Foundations.NaturalNumbers UniMath.Algebra.RigsAndRings UniMath.Algebra.Domains_and_Fields UniMath.NumberSystems.Integers UniMath.Algebra.Monoids