Alex

nevermind, solution found
http://tex.stackexchange.com/questions/5502/how-to-get-a-mid-binary-relation-that-grows

Quick question: can someone tell me how I am using \middle incorrectly to resize the \mid symbol in

$\left\{t \begin{pmatrix}
1 \\ -1
\end{pmatrix}\middle\mid t \in \R\right\}$

Using TeXStudio on Windows with MiKTeX distribution, does anyone know how not to get the warning

"pdflatex (file C:/ProgramData/MiKTeX/2.9/pdftex/config/pdftex.map): invalid entry for `\ProvidesFile{fetamont.map}': both ps_name and font file missing"

http://math.stackexchange.com/questions/765677/question-about-flow

I believe this should be a pretty quick question to answer if someone here is familiar with the flow of a vector field...

If $A$ is an $m \times n$ nonzero matrix, $B,C$ are $m \times m$ invertible matrices, and $BA = CA$, can I assert that $B = C$ or is there a case where this isn't necessarily true?

Working on a proof that the reduced row echelon form of a matrix is unique for homework and this would give me the final step I need for my proof.

I am trying to prove that if the coefficient matrix of a system of $m$ linear equations in $n$ unknowns over a field $F$ has rank $m$, the the system has a solution.

If I let $A$ be the $m \times n$ coefficient matrix with rank $m$ and I let $b$ be an arbitrary column vector in $F^m$, could I show that the rank of $A$ and the rank of $A$ augmented by $b$ must both be $m$?