Category:Examples of Norms

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This category contains examples of norms.

Let $\struct {R, +, \circ}$ be a division ring with norm $\norm {\,\cdot\,}_R$.

Let $V$ be a vector space over $R$, with zero $0_V$.


A norm on $V$ is a map from $V$ to the nonnegative reals:

$\norm{\,\cdot\,}: V \to \R_{\ge 0}$

satisfying the (vector space) norm axioms:

\((\text N 1)\)   $:$   Positive Definiteness:      \(\ds \forall x \in V:\)    \(\ds \norm x = 0 \)   \(\ds \iff \)   \(\ds x = \mathbf 0_V \)             
\((\text N 2)\)   $:$   Positive Homogeneity:      \(\ds \forall x \in V, \lambda \in R:\)    \(\ds \norm {\lambda x} \)   \(\ds = \)   \(\ds \norm {\lambda}_R \times \norm x \)             
\((\text N 3)\)   $:$   Triangle Inequality:      \(\ds \forall x, y \in V:\)    \(\ds \norm {x + y} \)   \(\ds \le \)   \(\ds \norm x + \norm y \)