hello ryan,
> But all of this would be cleaner if I wasn't doing the TeX->LaTeX
> after the fact using regexp.
in order to get the tex output you want for fractions and matrices,
maybe all you need to do is load mactex-utilities.lisp.
default:
(%i1) tex (aa / bb);
$${{aa}\over{bb}}$$
(%o1) false
(%i2) tex (matrix ([aa, bb], [cc, dd]));
$$\pmatrix{aa&bb\cr cc&dd\cr }$$
(%o2) false
with mactex-utilities:
(%i3) load ("mactex-utilities");
(%o3) /usr/local/share/maxima/5.9.2.6cvs/share/utils/mactex-util\
ities.lisp
(%i4) tex (aa / bb);
$$\frac{aa}{bb}$$
(%o4) false
(%i5) tex (matrix ([aa, bb], [cc, dd]));
$$\begin{pmatrix}aa & bb \\ cc & dd \\ \end{pmatrix}$$
(%o5) false
hope this helps,
robert dodie