The identity element (also denoted , , or 1) of a group or related mathematical structure is the unique element such that for every element . The symbol "" derives from the German word for unity, "Einheit." An identity element is also called a unit element.
Identity Element
See also
Binary Operator, Group, Group Involution, MonoidExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Identity Element." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/IdentityElement.html