Suite CAS 4 Gaussian elimination procedure
{Dyadic Product Matrices \\
and Gaussian elimination procedure\\
\{row marker for addition and result\}\\
\{row marker with multiplication factor\}\\
+ id\\\\
first row plus (-2) \times third row \\
(\{\{1\},\{0\},\{0\}\} \{\{0,0,-2\}\}) + id\\