# Overview

## Feyn: a Metafont for Feynman diagrams

Version @version NA@.

This package is intended to produce relatively simple Feynman diagrams, for example within equations.

This package differs from Thorsten Ohl's feynmf/feynmp package. FeynMP works by creating Metafont or MetaPost figures using a preprocessor. It's more general than this package, but is at its best when creating relatively large diagrams, for figures. In contrast, the present system consists of a carefully-designed font with which you can easily write simple diagrams, within equations or within text, in a size matching the surrounding text size.

The propagators and vertices which are implemented are those which seem to appear most often in non-figure displays (the practical definition of ‘appear most often’ is ‘which I wanted’ and ‘which people asked me for’). I have no current plans to extend the package further, but I'm willing add other features if you can make a case for them, and they fit within the package's remit of ‘diagrams for use in equations’.

There is further documentation, plus numerous examples, in the package documentation (feyn.pdf).

## Installation

Extract the package file from the distribution file using latex feyn.ins. The resulting feyn.sty should be installed in the usual location for style files -- that is, something like texmf.local/tex/latex/feyn.sty. The Metafont source files *.mf should be installed in a directory with a location such as texmf.local/fonts/source/feyn/ (on a system which has the command, kpsepath mf will indicate the possibilities here, but these typically include the current directory). That should be all you need to do as regards the installation of the fonts -- if your TeX setup is installed correctly, then the usual font-generation commands (such as mktexpk for example) should work as normal, and they should be invoked by default when you LaTeX the feyn.dtx file.

You should be able to find generic instructions for installing LaTeX files at http://www.tex.ac.uk/cgi-bin/texfaq2html?label=installthings