Matrix gauss continuation Suppose we have the matrix $4\times4$, $R_1 =(0,0,1,1)$, $R_2=(0,1,1,0)$, $R_3=(1,1,0,0)$, $R_4(1,0,0,0)$ and suppose we want to see the rank.The difficult part is that you cannot order them somehow to use gauss.Any ideas what should be done in such situations?

Re-ordering the rows does not change the rank. We can therefore consider the matrix 
$$
A
=
\begin{pmatrix}
1&0&0&0\\
1&1&0&0\\
0&1&1&0\\
0&0&1&1
\end{pmatrix}
$$
Clearly $\det A=1$ so $A$ has rank four.
Of course, this method does not generalize to matrices with rows that are "less nice".
