Elementary transvection matrix (source code)

= Elementary transvection matrix
{title2=$I+tE_{ij},\quad i\ne j$}

This <matrix> adds $t$ times coordinate $j$ to coordinate $i$. Left multiplication performs the corresponding row addition. Such matrices generate the <special linear group over a finite field>: row elimination also realizes signed interchanges and compensating diagonal scalings using products of these matrices.