You probably already know about the two packages that you can use to typeset Fitch-style natural deducation proofs in LaTeX.  Here's another, which you may be interested in if you use Barker-Plummer, Barwise, and Etchemendy's popular logic text Language, Proof, and Logic. It makes proofs like this: I've taken Etch's original style file and Dave's … Continue reading LaTeX Package for Typesetting Fitch Proofs LPL-Style