On 2017-08-12, rjf <[email protected]> wrote: > seems to me that asking for the "sign" of b^(1/3) in the complex domain > is nonsense.
After thinking about this some more, I think maybe you're right -- SIGNDIFF-SPECIAL, which is doing the c^3 - b*c --> c - (b*c)^(1/3) that leads into trouble, should maybe inhibit that approach when domain = complex, since it can't work in general. But in this case, b and c are assumed to be positive (and they're declared real for good measure) so taking roots doesn't lead to any strangeness. So maybe the answer is that the usual simplification (b*c)^(1/3) --> b^(1/3)*c^(1/3) should be allowed even though domain = complex. I'm just thinking out loud here, sorry it doesn't make sense yet. All present are invited to join in. best Robert Dodier -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
