--- In qalam@yahoogroups.com, "Nicholas Bodley" <nbodley@...> wrote:

> Then, there are such expressions as Ga_(x)Al<sub>(1-x)

</sub>As,

> where the amount of Ga and Al totals 1.
> (I didn't check to see whether those are the correct HTML tags,

btw.)

>
> This surely does seem to be getting into the matter of Unicode's
> definitions, versus rendering details independent of Unicode. At

the

> moment, I'm thinking that including super and sub numerals was a
> "concession" or a convenience that does not strictly follow

Unicode's

> primary intent; might well be wrong on that.

It certainly feels that way. If you want to write a_ij,
you can write it a_i�x2063;j to make it clear that there
are two subscripts, rather than a subscript which is a product, for
which you could use a_i�x2062;j. (This HTML won't work -
you have to convert the hex to decimal manually.) However,
although it has 'invisible times' U+2062 and 'invisible separator'
U+2063, there is no mechanism for forming subscripts! The use of
subscript digits in XML documents 'is discouraged'. Unicode for
Maths is discussed at http://www.unicode.org/reports/tr25/ . On the
other hand IF your browser/font supports it, you can write base 10
vulgar fractions to your heart's content - use fractional slash
U+2044! (It failed for IE 6.0, but maybe that's because I wasn't
using the right font.) You can only use digits, and that concept
excludes subscript digits.

Richard.