On 5/15/06, Robert Dodier <robert.dodier at gmail.com> wrote:
>
> On 5/15/06, Barton Willis <willisb at unk.edu> wrote:
>
> OK by me. But can we suppress some of the asksign nuttiness
> that crops up in rectform ?
What "nuttiness" did you have in mind? Do you mean you want to suppress it
in the featurep case, or in general?
What do you suggest the value of featurep(sqrt(x),real) be in the absence of
asksign? I can think of several reasonable answers:
false -- because of course for x<0 it is imaginary
x >= 0 -- a boolean expression
true -- because we treat the domain of sqrt as real
The problem with the boolean expression is that most users of featurep would
want to dispatch on the value, and aren't prepared to themselves return a
conditional expression....
>
> > (4) Maxima should signal domain errors ASAP.
>
> Well, I'm not so sure about that.
Robert, I know that errors are inconvenient in non-interactive usage, but as
Barton says, they catch the problem before it propagates (possibly giving
incorrect results). If you need to catch the error, what is wrong with some
error handling mechanism (preferably more sophisticated than errcatch...)?
-s