# Problems with mfplain

When I read the file mfplain into Metapost, I get about a dozen error messages complaining about redundant and inconsistent equations. It's hard to believe that there is really anything wrong with mfplain. Any idea what might be going wrong ?

The details of the interaction are as follows:

C:\Program Files (x86)\MikTex\miktex\bin>mpost
This is MetaPost, version 1.504 (MiKTeX 2.9)
**\relax
(mpost.mp (C:/Program Files (x86)/MikTex/metapost/base/plain.mp
*\input mfplain
(C:/Program Files (x86)/MikTex/metapost/base/mfplain.mp
basic constants and mathematical macros,
macros for converting units,
! Inconsistent equation (off by 2.77794).
;
l.230 mm*bpppix_=2.83464;
pt*bpppix_=0.99626;
?
[[ followed by a dozen or so similar messages ]]

-
I don't think that mfplain is to be loaded when plain.mp is already loaded: they are designed for doing different things. –  egreg Nov 9 '12 at 18:36

mfplain.mp is designed to do very different things than plain.mp; if you want to build a Metafont as a Type3 font with Metapost, then something like

mpost -mem=mfplain cmr10.mf


will do.

Since version 1.5 (if I remember correctly), mpost doesn't really load .mem files any more, but it loads plain.mp by default. To get mfplain.mp in interactive mode, you can also call mpost -ini:

egreg% mpost -ini
This is MetaPost, version 1.504 (kpathsea version 6.1.0)
**mfplain
(/usr/local/texlive/2012/texmf-dist/metapost/base/mfplain.mp

@bubba: You can probably also invoke it as just mfplain. –  SamB Apr 12 at 17:32