MathGloss

Let $(V,F)$ be a vector space. A function $\langle\cdot,\cdot\rangle: V\times V \to F$ is an inner product on $V$ if

  1. it is bilinear;
  2. it is commutative;
  3. $\langle v, v\rangle \geq 0$ for all $v \in V$ and $\langle v,v\rangle = 0$ if and only if $v=0$.

Wikidata ID: Q23924662