Lemma ringminusdistr' { X : commring } ( a b c : X ) : (a * (b - c))%ring = (a * b - a * c)%ring. Proof. intros. rewrite ringldistr. rewrite ringrmultminus. apply idpath. Defined.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.Combinatorics.Maybe. Require Import UniMath.Combinatorics.StandardFiniteSets. Require Import UniMath.Algebra.Domains_and_Fields. Require Import UniMath.Algebra.RigsAndRings.