Definition from Algebra by Bourbaki, II §1, no.
Require Import UniMath.Algebra.Modules.Core. Require Import UniMath.Algebra.Groups. Require Import UniMath.Algebra.Monoids. Require Import UniMath.Algebra.RigsAndRings. Require Import UniMath.Foundations.Preamble. Require Import UniMath.Foundations.Sets.