Improving the output of the standard eq package

[Chris Webb]

I have a slightly modified version of the standard Lout eq package which
I've been using to set the odd simple equation in my documents. The modified
eq makes the lower case Greek letters from the Symbol font fit in better
with the italic Latin letters from the Times font by slanting them in the
same way as Groff does.

I've put a copy of the patch against Lout 3.31 at

  http://home.arachsys.com/~chris/lout-3.31-eqsl.patch

In brief, this arranges for some postscript to be prepended to documents
containing equations, generating a Symbol-Slanted font by transforming the
standard Symbol font. There's an automatically generated AFM file for this
derived font in fonts/Symb-Sl. I then define @SymI by analogy with @Sym, and
use it for the lower case Greek letters in eqf.

The lower case Greek letters in the resulting font look surprisingly good
alongside Times-Italic, as they already have an 'upright italic' styling in
the standard Symbol font. The result isn't quite perfect: both Symbol and
thus also the derived Symbol-Slanted seem to have slight baseline issues
against Times-Italic, but this patch at least fixes the slant inconsistency.

Here are two PDF files to demonstrate:

  http://home.arachsys.com/~chris/lout-eqwithoutsl.pdf
  http://home.arachsys.com/~chris/lout-eqwithsl.pdf

Unfortunately, I have to conditionalise the use of Symbol-Slanted on the
backend in use. The postscript magic won't work in PDF, and I don't know
enough about PDF to determine whether it's possible to do something
equivalent. Can anyone more knowledgeable about PDF comment further? Is
there an alternative solution for PDF?

Cheers,

Chris.