Hi Dima, On 30 Dez., 07:33, Dima Pasechnik <dimp...@gmail.com> wrote: > On Friday, December 30, 2011 2:28:56 PM UTC+8, Dima Pasechnik wrote: > > > Is it legal to compare real elements of different number fields?
It is certainly legal to compare for *equality*, provided that both number fields are equipped with an embedding into the complex fields, such that comparison can be done there (i.e., after coercion). > > E.g. on MacOSX: > > sage: F = RealField() > > sage: k.<i> = NumberField(x^3 +x + 1) > > sage: F(1).abs() > 0*i > > False > > > while on Linux the same code returns True (this is the reason for the bug > > in #12208). Interesting. I think the answer "True" is wrong. Namely, ">" and "<" are relations, i.e., subsets of the cartesian product of k with itself. Since k is not ordered, both subsets are empty. Hence, I would prefer that both "F(1).abs() > 0*i" and "F(1).abs() < 0*i" return False. Cheers, Simon -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
