On Fri, Apr 24, 2009 at 9:03 AM, Robert Miller <rlmills...@gmail.com> wrote: > > sage: x = polygen(ZZ) > sage: f = 2*x^2 > sage: f.mod(2)==0 > False
You should do "f.mod?" and read the docstring, which says: "Return a representative for self modulo the ideal I (or the ideal generated by the elements of I if I is not an ideal.)" I believe f itself is a representative for f mod the ideal 2. :-) You're assuming that the mod function does something interesting, but it is in this case just some generic code which does what its definition says, which in this case happens to be nothing. So make it better! :-) William > sage: type(f.mod(2)) > <type > 'sage.rings.polynomial.polynomial_integer_dense_flint.Polynomial_integer_dense_flint'> > > Even this doesn't work: > sage: R.<x> = ZZ[] > sage: f.mod(2*R)==0 > False > > But last I checked, 2 | 2x^2. > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---