[OS X TeX] Aligning equations with comments

[R. Vijay Krishna]

On Mar 18, 2011, at 3:42 PM, David Arnold wrote:

> I need to align x-terms, operator, y-terms, equal sign, and right-hand sides in their own columns, while keeping my comment space to the right. I also need to underline that second equation before writing that third equation.

I think systeme <http://mirror.math.ku.edu/tex-archive/macros/generic/systeme/systeme_doc_fr.pdf> does some of what you're looking for.  Unfortunately, French is but a distant memory for me.

Vijay