Definition:Identity (Abstract Algebra)/Left Identity

Definition
Let $\left({S, \circ}\right)$ be an algebraic structure. An element $e_L \in S$ is called a left identity iff:
 * $\forall x \in S: e_L \circ x = x$

Also known as

 * Left neutral element

Also see

 * Right Identity
 * Two-Sided Identity