> something like
> {a \over b} or maybe \frac... [I don't really care]
>
> The new version would be
> (\tag 1 {\tag 2 {\frac {\tag 3 a} {\tag 4 b}}}}
Yes, this is what I meant.
> where internal to maxima we have a hash table that has, for every
> expression sent to the front end, an index into the formatted (not
> the internal) form. That is, hashing
> (1 2 3) or maybe just 3
> would be a pointer to the location of the "a" in expression
> 1.
> (1 2) or just 2 would be the whole fraction.
Right.
> calling the simplifier on the formatted form produces a simplified
> internal form. It is not the same tree as we started with, but should
> be pretty close.
>
> Anyway, selecting terms 20 to 24 of a 100 term polynomials would
> (I guess) require communicating 2 or more index sets to the back end,
> where the pieces would be assembled.
I can do this. But we might do more later, by communicating something like
an XML-like-subdocument, whatever the use of such a facility might be...
> On the Texmacs side, you would have to strip off the tags and save
> the index numbers, and support pointing/selection.
On the TeXmacs side, I would have a typesetting construct "tag",
which takes two arguments : an invisible label, and the tagged expression.
Whenever you select an expression, I might return all corresponding tag
information. For other purposes, the tags might be stripped.
> This is now
> supported by commercial macsyma and mathematica, as well as the
> very nice interactive systems http://www.livemath.com/
> by Allan Bonadio.
No problem, this can be implemented in a few hours inside TeXmacs.
> ( In fact, a nice solution to the user interface
> but not free) would be to take Bonadio's
> system and attach Maxima to it. You should in any case
> take a long look at Bonadio's design!)
I'll take a look when I have time. Anyway, I do have lots of ideas waiting
to be implemented, so time is more a problem as ideas...
What is interesting about TeXmacs, is that many computer algebra systems
have already been linked (up to 8 at this moment), so the comments by
different people might lead to a free greatest-common-useful interface.
Don't forget that TeXmacs il *also* an extensible typesetting system :
you may directly incorporate your computations in TeXmacs articles.
Finally, TeXmacs will become a WEB-authoring tool, as soon as the
converters with Html/Mathml/Xml are ready...
Yours,
Joris