Given that $A$ is a real, rectangular matrix of dimension $m \times n$ and
$$\begin{align} A = \left[\begin{array}{c} I \\ e^{\intercal} \\ -e^{\intercal}\end{array}\right] \end{align}$$
is represented in block matrix notation. What does $A$ look like, given $e$ is a vector of $1$'s?
It might look something like this:
$$\left[\begin{array}{cccccc} 1 & 0 & 0 & 0 & 0 & 0\\ 0 & 1 & 0 & 0 & 0 & 0\\ 0 & 0 & 1 & 0 & 0 & 0\\ 0 & 0 & 0 & 1 & 0 & 0\\ 0 & 0 & 0 & 0 & 1 & 0\\ 0 & 0 & 0 & 0 & 0 & 1\\ 1 & 1 & 1 & 1 & 1 & 1\\ -1 & -1 & -1 & -1 & -1 & -1 \end{array}\right]$$
