🚀 go-pugleaf

Hi, I am seeking a way (in LaTeX) to align modifiers of multiple equations
in the eqnarray environment.  For example,

	w_t = Aw_x + Bw_xx       0 < x < L,  t >= 0          (1)
     w(x,0) = f(x)               0 < x < L                   (2)

The way I understand it, the LaTeX eqnarray environment only allows for
3 columns in the 'array'.  These are usually the left-hand side, the 
equals symbol, and the right-hand side.  I have been trying to line
up the modifiers ( 0 < x < L, etc.) by inserting spaces (tedious and
not very good TeX-ing!).

Suggestions?  I suppose I could always read the TeXbook and use \eqalign,
but I'm somehow reluctant.  Does anyone have a style file that has a
fourth column in the eqnarray environment?

Thank you for your consideration.

Mike Stoecker