[metapost] Labels cause errors in the postscript file.

[Laurence Finston]

> 
> \vbox to \vsize{\vfil
> \line{\hskip 2cm\epsffile{trial.30}\hss}
> \vss}
> 

This example wasn't too good.  `\vskip2cm',  for example, would be better than
`\vfil'.  If the graphic is supposed to be centered even if its combined
height and depth are greater than  `\vsize', then `\vss' should be used
instead of `\vfil'.
 
Laurence Finston
http://www.gnu.org/software/3dldf/LDF.html