Hi Fabrizio
> He is using it in preparatory course
> for math teachers.
> This is very good because there are
> lots of future math teachers who might
> use Maxima in the future!
> Moreover we get bug reports from them,
> one of which is very serious:
> solve([a=b,b=3],[a]).
if b is not a variable, then maxima thinks that b=3 in an inconsistent
equation. Try
(%i1) solve([a=b, b=3], [a, b]);
(%o1) [[a=3,b=3]]
or
(%i2) load(solver)$
(%i3) Solver([a=b, b=3], [a]);
(%o3) [[a=3]]
(Solver considers b as a variable and not a parameter).
HTH,
Andrej