more eqn man page updates

[G. Branden Robinson]

Hi all,

With Damian working on an updated user's guide as well, it appears to be
the season don one's sequins and work on eqn.  (I assume no one at Bell
Labs ever pronounced it that way.)

I have updated the eqn(1) man page again, this time with a couple of
examples and a further revised discussion of the spacing and typeface
style assignment system that is unique to GNU eqn.

I'd appreciate feedback since I expect this material to go into groff
1.23.0.  You might look at your installed eqn(1) man page first to get a
feel for how much it omits.

This is not nearly complete.  There are still 3 major tasks and 1 minor
task to undertake.  But it might be as far as I get before release.

A.  Document precisely how the spacing types affect automatic spacing.
    Mostly this is a matter of reading and understanding the code in

https://git.savannah.gnu.org/cgit/groff.git/tree/src/preproc/eqn/list.cpp?h=1.23.0.rc4

    and then performing experiments and writing up the findings.

B.  Document all the primitives not already documented; this means the
    ones from AT&T eqn.

C.  Document all the predefined macros not already documented; this
    means the ones from AT&T eqn.

d.  Document GNU eqn's use of *roff name spaces.  It uses identifiers
    starting with "0" for various internal purposes.  But also the
    string `10` and the register `MK`, according to a source comment,
    for "eqn.ms" compatibility.  This appears to be a reference to AT&T
    (and Berkeley) ms, which do appear to assume these names.  But groff
    ms does not, and because GNU eqn's output heavily employs GNU troff
    language extensions anyway, the idea that we should retain these
    latter two names is a bit dubious to me.

I'm attaching a copy of eqn.1 and eqn.pdf for your nroffing or PDF
viewing pleasure.

Regards,
Branden

eqn.1
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eqn.1.pdf
Description: Adobe PDF document

signature.asc
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