# pdflatex with simple Feynman

Haines Brown haines at histomat.net
Mon Dec 12 13:36:21 CET 2022

I have no trouble witn Feynman diagrams in a LuaLaTeX document, but
find it difficult to construct one in a LaTeX document. I construct a
c.tex file with the sample from the fmf manual:

\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{feynmp-auto}
\begin{document}
\begin{fmffile}
\begin{fmfgraph*}(40,30)
\fmfpen{thick}
\fmfleft{i1,i2}
\fmfright{o1,o2}
\fmf{fermion}{i1,v1,o1}
\fmf{fermion}{i2,v2,o2}
\fmf{photon,label=$q$}{v1,v2}
\fmfdot{v1,v2}
\end{fmfgraph*}
\end{fmfile}
\end{document}

When I do $pdflatex c.tex I get error: ... [Loading MPS to PDF converter (version 2006.09.02).] ) (/usr/local/texlive/2022/texmf-dist/tex/latex/epstopdf-pkg/epstopdf-base.sty (/usr/local/texlive/2022/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg)) ! Argument of \begin has an extra }. If from a command prompt before running pdflatex I do:$ fm \mode=localfile;' input c.tex

in the result c.log I get

! Forbidden token found while scanning to the end of the statement.
<inserted text>
;
end
l.11 \end
{fmfgraph*}
A previous error seems to have propagated,
causing me to read past where you wanted me to stop.
I'll try to recover; but if the error is serious,
you'd better type E' or X' now and fix your file.

--

Haines Brown
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