On 5/22/07, Michel <[EMAIL PROTECTED]> wrote: > I do not agree with the radical statement that there should not be > (non-canonical) > coercions in that direction. There is a coercion from QQ to ZZ.
You misunderstand -- by "coercion" David Roe meant a canonical coercion, which is defined by the _coerce_impl_ method in SAGE. There is no canonical coercion QQ --> ZZ. > Why shouldn't there be a coercion from a polynomial ring to its > base ring? Nobody says there shouldn't be a coerce map. But it should not be automatic or canonical, i.e., called automatically in simplifying arithmetic expressions. > Sage should mimic the way mathematicians think. > > I agree that perhaps this situation can be recognized automatically. -- William Stein Associate Professor of Mathematics University of Washington http://www.williamstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
