An D21: Algebraic structure $R = (X, +, \times)$ is a ring if and only if

(1)	$G = (X, +)$ is an D23: Abelian group
(2)	$H = (X, \times)$ is a D264: Semigroup
(3)	The D20: Enclosed binary operation $\times$ is a D557: Distributive binary operation over $+$