I have some problems to understand the polyhedron projection based on Fourier-Motzkin. The projection is defined like $Q := \pi_k(\{x \in R^n:Ax \geq b \}) = \{(x_1,...,x_k)^T \in R : \exists x_{k+1},...,x_n \in R : (x_1,...,x_n)^T \in P\}$
for an $k$ between $1$ and $n$ ($1\leq k \leq n$) while $P =\{x \in Z^n : Ax \geq b\}$ is a polyhedron.
Here now a example: Given Matrix $ A = \left( \begin{matrix} 0 & 0 & 1 \\ 0 & 0 & -1 \end{matrix} \right) $ , $ b = \left( \begin{matrix} 1 & 1 \end{matrix} \right) $ and $k =2$
How does this should work? It's maybe a dumb question, but I hope u can give me a understandable answer. Should i just delete the rows greater than $k$? And also this question has nothing to do with any homeworks, because I'm not a student, just interested in math.