lemmon style proof for logic

Question

Does exist a package for Lemmon style proof in Logic? something like: http://logik.phl.univie.ac.at/~chris/gateway/formular-uk-bau.html

thanks

Answer 1

There is a package which is not on CTAN but can be found at: http://phloxgroup.wordpress.com/2010/03/22/lemmon-style-natural-deduction-proofs-in-latex/ (for some reason¹, the author saved the file as a .doc file, just save as .sty file and it will work).

I haven't thoroughly tested the package, but you can do things like:

\documentclass{article}
\usepackage{nd3}
\begin{document}
    \begin{ND}[Anothter Proof][ ][\awidth{the proof}][\rwidth{the proof}][.8\linewidth]
        \ndl{} {$a=a$} {$= $I}\label{1}
        \ndl{} {$\forall x\,x =x$ }{\ref{1},$\forall$I}\label{2}
    \end{ND}
\end{document}

(example taken from the manual)

You may also want to take a look at the packages listed at: http://www.logicmatters.net/latex-for-logicians/ maybe you'll find something interesting

--

¹Actually, the reason is explained in the blog