On Mon, Nov 21, 2011 at 4:50 PM, David Roe <r...@math.harvard.edu> wrote: > The coercion graph in Sage is supposed to be transitive. This > assumption is explicit in the documentation of sage.structure.coerce > for example. But we have the following: > > sage: R = Zmod(6) > sage: S = Zmod(3) > sage: T = GF(3) > sage: T.has_coerce_map_from(S) > True > sage: S.has_coerce_map_from(R) > True > sage: T.has_coerce_map_from(R) > False
I think that should return True, since there is a canonical map from Z/6Z to GF(3). > Any opinions on which of these results should change? I'm thinking > about such coercions between finite rings in the context of residue > fields and quotients of p-adic rings, so you can also ask yourself if > you want a coercion from Zmod(250) to Zp(5).quotient(5^3). I want such a coercion, since again there is a canonical map Z/250Z --> Z/5^3Z \isom Z_5 / 5^3 Z_5. > David > > -- > 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 > -- William Stein Professor of Mathematics University of Washington http://wstein.org -- 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
