Elementary Column Matrix is Nonsingular
Theorem
Let $\mathbf E$ be an elementary column matrix.
Then $\mathbf E$ is nonsingular.
Proof
From Elementary Column Matrix for Inverse of Elementary Column Operation is Inverse it is demonstrated that:
- if $\mathbf E$ is the elementary column matrix corresponding to an elementary column operation $e$
then:
- the inverse of $e$ corresponds to an elementary column matrix which is the inverse of $\mathbf E$.
So as $\mathbf E$ has an inverse, a fortiori it is nonsingular.
$\blacksquare$