- $\forall x \in S: x \circ e = x = e \circ x$
Thus it is justified to refer to it as the identity (of a given algebraic structure).
This identity is often denoted $e_S$, or $e$ if it is clearly understood what structure is being discussed.
Pages in category "Definitions/Identity Elements"
The following 10 pages are in this category, out of 10 total.