proposition: Lemma ringminusdistl { X : commring } ( a b c : X ) : (b - c) * a = b * a - c * a.
proof: Proof. intros. rewrite ringrdistr. rewrite ringlmultminus. apply idpath. 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