Well, apparently, you don't. I downloaded a bunch of mathematical fonts, including the ones Donald Knuth designed for LaTEX, but none of them were useful for a word processor. The multiple lines of a complex equation seem to be well outside the scope of a word processor's capabilities.
Supposedly LaTEX can do it, but I didn't have time to learn LaTEX, so I whipped these up in a graphics program:
and inserted them into my document as graphics.
As you can see, these equations are kinda difficult to reproduce in a word processor. Still, if anyone can figure out how to do it, please let me know. It would be nice information to have for next time.
Humorous footnote: it took longer to produce these equations on paper than it did to write and run the Perl code that uses them. Computers win again!