Andrew Sell

A Deffiniton of Matrix Multiplication

Basically...

$A\in {\mathbb {R} }^{m\times n}$, $B\in {\mathbb {R} }^{n\times p}$

Turns into...

$(AB)\in {\mathbb {R} }^{m\times p}$

Where $AB$ are magically

$(AB)_{i,j}=\sum _{r=1}^{n}A_{i,r}B_{r,j}$

Make sense?...