Leo Butler wrote:
>
> My narrow point is that sqrt is a multi-valued function. Repeated
> invocations must either know that they are related, i.e. you are referring
> to the same element in the same branch (to the same 'sqrt(1)'), or pursue
> the complete collection of branches.
I would say the opposite. Modern versions of maple try to be very correct
with such stuff and become almost unusable. In general i think it is more
valuable that a CAS does as much simplification as possible, even if it
assumes too much. Producing a two pages long result is next to useless.
In most cases the CAS will get the continuation correct, and in any case,
it is up to the user to be aware that algebraic functions have several
continuations.
--
Michel Talon