Re: Superscripts, subscripts and equations

[Jeff Kingston]

> using a superscript on a line within a paragraph yields
> the line's distance to the previous line being larger than
> the regular paragraph inter-line space.

You could work around this, either by changing your line
spacing globally from 1.2fx (or whatever) to 1.2fo, or by
hiding the true height of the subscript by enclosing the
inline equation in a symbol that made it appear to have
zero height, such as

    def @ZeroHeight right x { @OneRow { ^//0io x } }

Given the height at which Lout places the superscript,
it is really forced to enlarge the line gap, since it
does not know that it would not overstrike the previous
line otherwise.  Indeed, if there is a descender just
above the superscript, there would be an overstrike.

Alternatively, if the aim is to make the superscript
lower (and I guess it is), then probably we need the
effect of @VSqueeze in file eqf.  I just don't know
now whether Knuth's rule for inline vertical
squeezing is the same as for squeezing under square
root signs and similar things.  If it is, then we
just need an option to @Eq that has the effect of
applying @VSqueeze to the entire equation; instead
of

    1f @ZUnit 1f @YUnit @Body

on line 1693 of eqf, we need 0.7f @ZUnit...

In any case there would need to be a separate
symbol, perhaps a new version of @E, or perhaps
@PE say, which invokes @Eq passing 0.7f as the
vsqueeze option, rather than the default 1f.
Lout can't tell automatically that it is inside
a paragraph, as TeX does with its various "modes",
so a separate symbol would be needed.

I'm happy to look at this for the next release.
I think a change to the spec of @E is the way
to go, since it was always advertised as being
good for inline equations.  Of course, if
someone wanted to get hold of the TeXBook,
sort out the spec, implement the changes, and
send over a diff file, it would happen faster.

Jeff