[plt-scheme] Generating LaTeX source from Scheme

>Please introduce and post your code in the Scheme Cookbook if it's not
>too big :-)
>Otherwise just introduce it there, but either way, consider uploading
>it to PLaneT, the Scheme library repository:

I suspect it's not good enough for public consumption; as I said, it
was my first real programming in Scheme. Noel has a copy of the HTML
part. Maybe someone more experienced than I can take a look at all of
it, clean it up, make obvious improvements that I've missed, and post
it. I've no objection except that it may be below threshold. --PR