Re: [Groff] Re: heirloom eqn

[Gunnar Ritter]

Werner LEMBERG <address@hidden> wrote:

> > geqn seems to ignore part of explicit provided spaces "~" in the
> > above example (it seems to be the default spacing anyway).  Is this
> > intended behaviour: "increase spacing only by the difference of
> > explicit provided space and default space"?
>
> It seems so.  I've compared the distances of the equations
>
>   x = y + z
>
> and
>
>   x~=~y~+~z
>
> in the original eqn2e.ps documentaion file `Typesetting Mathematics --
> User's Guide (Second Edition), page 1 and 2.

This seems to have been generated using a later variant
of eqn than the one of the Heirloom tools, which descends
from the one distributed with OpenSolaris.

Plan 9 has a variant of the original eqn that has been
extended to provide more elaborate spacing; without
explicit spaces, it generates a "\|\^" before the
equation sign instead of only a "\|", as the OpenSolaris
and (the fixed) Heirloom variants do. Maybe the version
with which the eqn2e.ps file has been generated was
similar to the Plan 9 one.

Since much of the actual appearance depends on the fonts,
it might be interesting to look at the first edition of
the eqn user's guide as printed on a CAT, as in the
hardcopy of the 7th edition manuals. Unfortunately, I
currently do not have my copy at hand.

Gunnar