[metapost] Problem with macros file

[Nicolas FRANCOIS]

Hi.

I have a reccuring problem with this situation : I have a metapost file
containing some "btex gnagnagna etex" code. As I want to use latex
commands, I have a preambule like this :

verbatimtex
%&latex
\documentclass{arnaudies}
\begin{document}
etex

input courbes;

beginfig(401);
  z.a = (0,0);
  label.llft(btex $A_1$ etex,z.a);
endfig;

verbatimtex
\end{document}
etex

end

The problem comes from "input courbes". courbes.mp is a macro file (see
Syracuse site : http://melusine.eu.org/syracuse/metapost/) which also
contains some "btex gna etex" stuff, but no preambule. So this code fails
with a message signaling that courbes.mpx can't be built.

The only solutions I have found so far are :

1) some black magic consisting in doing "export TEX=tex; mpost fic.mp
(error); export TEX=latex; mpost fic.mp (it works !)".

2) putting a preambule in courbes.mp, which sounds weird since the
original author didn't seem to need those additional lines.

Can you help me ?

\bye

-- 

                   Nicolas FRANCOIS
            http://nicolas.francois.free.fr
 A TRUE Klingon programmer does NOT comment his code