Template:Norm

&#x2016;&#x2016; {{documentation|content= This template may be used to enclose text between a pair of double vertical bars ({{unichar|2016|double vertical line}}), such as to denote the norm. It adds padding (of width 0.1 em) on each side inside the bars.

Usage
When $\|x\| < 7$, the function is positive.

The notation $\|x\| < 7$ means norm.