On Nov 28, 3:14 pm, Mike Hansen <mhan...@gmail.com> wrote: > On Sun, Nov 28, 2010 at 3:09 PM, John H Palmieri <jhpalmier...@gmail.com> > wrote: > > > I think it's this code in sage/rings/polynomial/ > > multi_polynomial_ring_generic.pyx: > > > def __contains__(self, x): > > """ > > This definition of containment does not involve a natural > > inclusion from rings with less variables into rings with more. > > """ > > try: > > return x.parent() == self > > except AttributeError: > > return False > > I think this code should be removed in favor of the default implementation. > > --Mike
That looks okay to me. I don't know why "This definition of containment does not involve...", but if you delete the code, then sage: A1.<a> = PolynomialRing(QQ) sage: A2.<a,b> = PolynomialRing(QQ) sage: A1(a) in A2 True I don't know if the original implementers didn't want this sort of containment, but deleting the code will change this behavior. -- John -- 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
