General ⇒ Equation numbering scheme problem

[nderby]

Hello LaTeX Community!

I am trying to set up an equation numbering system such that on page N, the equations are numbered Na, Nb, Nc, etc. Using the perpage package, this can be done simply:

\MakePerPage{equation}
\renewcommand{\theequation}{\thepage\alph{equation}}

But here's the problem: If page N only has one equation, I want that equation to be numbered N (rather than Na). Any idea how I can do this?

One idea I have is to name it N by default - but if there is more than one equation on the same page, go back and renumber that first equation as Na and then continue as above. This could be done by doing something with the AUX file. But I know very little about that. Any ideas?

Thanks so much!