ZZ and QQ live in their own worlds (sigh). sage: ZZ(8)^(1/3) 2 sage: ZZ(-8)^(1/3) 2*(-1)^(1/3) sage: ZZ(1)^(1/3) 1 sage: ZZ(-1)^(1/3) (-1)^(1/3) sage: QQ(8)^(1/3) 2 sage: QQ(-8)^(1/3) 2*(-1)^(1/3) sage: QQ(1)^(1/3) 1 sage: QQ(-1)^(1/3) (-1)^(1/3)
>>> RR(ZZ(-8)^(1/3)) ... TypeError: unable to convert '1.00000000000000+1.73205080756888*I' to a real number This shows that symbolic expression (-1)^(1/3) is understood as the complex principal root. Then AA((-1)^(1/3)) should raise an error. Currently sage: AA((-1)^(1/3)) -1 In the happy world, we should understand that (-1)^(1/3) gets on different values depending on the target parent. This coercion also seems questionable: >>> parent(ZZ(8)^(1/3)) Rational Field Indeed, weird. exponentiation should not use a general coercion and the type of the exponent should be treated differently from the type of the base. I agree. -- 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 sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/8420164b-051a-47a7-9e0e-969879c81336n%40googlegroups.com.
