While I'm thinking about it, here are a couple more things from LaTeX's
math stuff that might be useful to include in m-newmat:
The \stackrel command is listed as "a disguise for plain TeX's \buildrel",
much like \frac is a "disguise" for \over:
\def\stackrel#1#2{\mathrel{\mathop{#2}\limits^{#1}}}
There's also the \lefteqn command:
\def\lefteqn#1{\rlap{$\displaystyle #1$}}
The \lefteqn command is useful for doing partly-aligned equations, of the
sort that get displayed as:
long left-hand-side
= long right-hand-side part 1
+ long right-hand-side part 2
+ long right-hand-side part 3
Essentially, you'd write that in an eqalign (or something like it), as:
\placeformula
\startformula
\eqalign{%
\lefteqn{long left-hand-side}\qquad & \cr
&= long right-hand-side part 1 \cr
&\quad {}+ long right-hand-side part 2 \cr
&\quad {}+ long right-hand-side part 3 \cr
}
\stopformula
As can be seen, \lefteqn lets the long left-hand-side overlap the alignment
point, without shifting it excessively to the right. It's not perfect --
for one thing, if the left-hand-side extends farther to the right than the
right-hand-sides, the equation won't be centered -- but it's a good start
and works right most of the time. :)
- Brooks