Identity function

From CS2800 wiki
Definition: Identity function
If [math]A [/math] is a set, then the identity function on [math]A [/math] (written [math]\href{/cs2800/wiki/index.php?title=Id&action=edit&redlink=1}{id}_A [/math] or simply [math]\href{/cs2800/wiki/index.php?title=Id&action=edit&redlink=1}{id} [/math] if [math]A [/math] is clear) is the function [math]\href{/cs2800/wiki/index.php?title=Id&action=edit&redlink=1}{id} : A \href{/cs2800/wiki/index.php/%E2%86%92}{→} A [/math] given by [math]id(x)\href{/cs2800/wiki/index.php/Definition}{:=x} [/math].