The fixcmex package is supposed to restore the cmex font and make it scaleable using several sizes provided by amsmath, even if the lmodern package has been loaded which overrides it with the lmex font which has just a single design size.

As can be seen below, this does not work for me. The extension font is still set to lmex10, the \widetilde does not scale at all, and the \big delimiters are larger than they should be.

The strange thing is as follows: The core of the package is the \fixcmex@fix command, which should be executed automatically via \AtBeginDocument. I can tell that it is definitely being executed, but somehow it doesn't manage to replace the font. But if I just issue that command directly during the preamble, then the font is replaced.

So, why doesn't it work automatically as it should?

% \makeatletter\fixcmex@fix\makeatother% is we uncomment this, then scaleable cmex is used


This is pdfTeX, Version 3.14159265-2.6-1.40.16
 *File List*
standalone.cls    2015/07/15 v1.2 Class to compile TeX sub-files standalone
ifluatex.sty    2010/03/01 v1.3 Provides the ifluatex switch (HO)
   ifpdf.sty    2011/01/30 v2.3 Provides the ifpdf switch (HO)
 ifxetex.sty    2010/09/12 v0.6 Provides ifxetex conditional
 xkeyval.sty    2014/12/03 v2.7a package option processing (HA)
 xkeyval.tex    2014/12/03 v2.7a key=value parser (HA)
standalone.cfg    2015/07/15 v1.2 Default configuration file for 'standalone' c
 article.cls    2014/09/29 v1.4h Standard LaTeX document class
  size12.clo    2014/09/29 v1.4h Standard LaTeX file (size option)
 lmodern.sty    2009/10/30 v1.6 Latin Modern Fonts
   t1enc.def    2005/09/27 v1.99g Standard LaTeX file
 amsmath.sty    2013/01/14 v2.14 AMS math features
 amstext.sty    2000/06/29 v2.01
  amsgen.sty    1999/11/30 v2.0
  amsbsy.sty    1999/11/29 v1.2d
  amsopn.sty    1999/12/14 v2.01 operator names
 fixcmex.sty    2015/11/10 v1.0 Scalable math extensions font (Enrico Gregorio)

   t1lmr.fd    2009/10/30 v1.6 Font defs for Latin Modern
  ot1lmr.fd    2009/10/30 v1.6 Font defs for Latin Modern
  omllmm.fd    2009/10/30 v1.6 Font defs for Latin Modern
 omslmsy.fd    2009/10/30 v1.6 Font defs for Latin Modern
 omxlmex.fd    2009/10/30 v1.6 Font defs for Latin Modern
  • A new version fixing the issue has been uploaded to CTAN. – egreg Aug 5 '19 at 20:44
  • 4
    I'm voting to close this question as off-topic because it is a bug report – egreg Aug 5 '19 at 20:44