# Latex counters: modifying \numberwithin?

1. May 18, 2010

### honestrosewater

I am writing up some formal proofs using the proof and align environments. Each line in the proof needs to be numbered and will contain a formula and a statement referring to earlier lines in the proof that were used to derive it. I want to reset this counter for each proof. It should look something like this:
What's the easiest way to do this? Should I define a new proof counter and modify \numberwithin to reset the equation counter when proof is incremented? (I don't know how to do this.) Or should I skip using equation and just define my own counter that will increment with each new line in align? (I don't know how to do this either.)

Edit: Oh, duh, I'll just add \setcounter manually where I want it reset. Is there a way to get the proof environment to do this automatically?

Last edited: May 18, 2010
2. May 18, 2010

### diazona

Here's the definition of the proof environment from amsthm.sty:
Code (Text):
\newenvironment{proof}[1][\proofname]{\par
\pushQED{\qed}%
\normalfont \topsep6\p@\@plus6\p@\relax
\trivlist
\item[\hskip\labelsep
\itshape