Definition:Power (Algebra)/Integer/Knuth Notation

Definition
In certain contexts in number theory, the symbol $\uparrow$ is used to denote the (usually) integer power operation:


 * $x \uparrow y := x^y$

This notation is usually referred to as Knuth (uparrow) notation.

Note that Knuth (uparrow) notation is right-associative, and so:
 * $x \uparrow y \uparrow z$

is interpreted as:
 * $x \uparrow \left({y \uparrow z}\right)$

Some authors prefer to retain the parenthesis.