Thanks to Barton and Richard,
<snip>
>
> um, this is all much easier in lisp, but
> you could try op(teste,0) to get "+".
...
> Depending on what you are really trying to do, my guess is you should just
> learn a little lisp.
> and also maybe read this:
>
> http://www.cs.berkeley.edu/~fateman/papers/simplifier.txt
>
> while it is about 33 years old, it is still fairly accurate.
Actually this was an experiment. I do know lisp, and I've been trying
to figure out the innards. In the process of research, one of the
emails on the Maxima site lamented that little of Maxima is written in
Maxima. As a recovering programming language person, this whets my
curiosity. So I decided to try an experiment and write the project I
have in mind completely in Maxima, even though I already have a lisp
version of the code. Should be pretty straight forward, no?
Stay tuned :-)