proposition: Lemma module_mult_is_ldistr {R : ring} {M : module R} (r : R) (x y : M) : r * (x + y) = r * x + r * y.
proof: Proof. exact (pr1 (pr2 (pr2module M r)) x y). Defined.
imports: UniMath.MoreFoundations.Tactics UniMath.Algebra.RigsAndRings UniMath.Algebra.Groups UniMath.Algebra.Monoids