[Texmacs-dev] Math input / output from CAS (Axiom)

[Karl Hegbloom]

When I use mathematical input to an Axiom session from within TeXmacs, I
can't type the == for delayed assignment. It gets turned into the long
equal sign. That's alright, perhaps, as long as the right thing gets
sent to the Axiom process.

When Axiom outputs a matrix, it outputs a table wrapped in large [],
rather than a \matrix object.  So, when I paste that into a document,
then later on go to paste it back into an Axiom session, it's not a
matrix.  Try this:

     1. Open a new document in TeXmacs, and in there, open an \eqnarray*
        or \[ and enter a \matrix with a few columns and rows filled in.
     2. Start an Axiom session, then highlight and paste the matrix into
        the session.
     3. Take the output of that, highlight everything including the
        square brackets, and paste it into the next input line of the
        Axiom session. The result is not a matrix, but a List Matrix ?.

What's happening is that tables are seen as matrices. I suppose that's
alright, but maybe a table wrapped with large [] should have the []
silently stripped by the input stream filter.  The thing is that in
TeXmacs, there's a different object for a determinant and for a matrice.
Both are defined in mth-std.ts, and internally contain tables.  It just
seems like the output from the CAS should be a \matrix rather than a
\tabular.

It would also be nice to have automatic coercions from vector to column
matrix.

Another annoyance is that the Axiom output does not have the *
explicitly written into polynomials. Instead, the coefficient and
variable are juxaposed, and so they are typeset too close together, and
when you paste the expression back into Axiom, it doesn't work right.
Sometimes, I've noticed, it appears to do something, but gives incorrect
results. Usually, it signals an error about not having an operator
defined for the variable name.

Ideally, there would be a better communication format between Axiom and
TeXmacs.  LaTeX / TeX are not really designed to convey the semantics of
the expressions, only the appearance, isn't that right?  There's a lot
of research out there on this subject...

-- 
Karl Hegbloom <address@hidden>