On Mon, May 11, 2026 at 11:52:08AM +0800, Qian Yun wrote:
> On 5/11/26 11:49 AM, Waldek Hebisch wrote:
> >>
> >> I guess that Interval did not want to deal with inverse of
> >> [a,b] where a<0<b?
> >
> > Yes, we do not want this: this is moral equivalent of division
> > by 0.
> >
>
> So for the "^" with negative Fraction Integer argument,
> shall we give an error for all intervals, or just for
> intervals that contains 0?
Negative fractional power should be mostly eqivalent to computing
inverse and then positive power, but should avoid double
rounding impled by composition of operations. Negative
interval can not be raised to power 1/2, and it makes
sense to completely forbid raising negative numbers to
fractional powers (but current version allows this). But
if both lower bound and upper bound are positive, then negative
fractional power is well defined.
--
Waldek Hebisch
--
You received this message because you are subscribed to the Google Groups
"FriCAS - computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/fricas-devel/agNY8YeWqCp8OLSN%40fricas.org.
