Re: real subscripts and superscripts?

[Karl Berry]

    I want some sane way of writing i^2 and R^4 so I get tolerably-looking
    expressions with superscripts in both TeX andDocBook/HTML.

Sure.

First, with non-letter superscripts (numbers, +, etc.), you're fine with
the present @sup inside math, regardless of whether @sub/@sup mean text
inside math for TeX, because numbers are typeset by TeX in roman, not
math italic, in any case.

makeinfo presently outputs @math as <em>...</em>, which results in
italic sub/superscripts inside @math (as well as everything else),
regardless of their content.  That's inconsistent with TeX, but I think
it's expected and reasonable for HTML.

Implementing ^_ in makeinfo would allow for better matching of
input/output, i.e., allowing documents to use ^_ inside @math and get
the expected output.  I think that's desirable for its own sake,
separate from any question of @sub and @sup.

Anyway, it's alphabetic sub/superscripts where the question of whether
@sub/@sup means "text" inside math makes a difference to TeX (nothing
else).  I'll await Patrice's comments before finalizing the TeX versions
and documentation.  I don't feel that strongly about it.

karl