Definition:Non-Archimedean/Norm (Vector Space)

Definition
A norm $\left\Vert \cdot \right\Vert$ on a space $X$ is non-Archimedean it satisfies the ultrametric inequality:


 * $\left\Vert {x + y} \right\Vert \le \max \left\{ {\left\Vert {x} \right\Vert, \left\Vert {y} \right\Vert} \right\}$

for all $x, y \in X$.