Hi, I'd like some confirmation for the patch at http://www.sagetrac.org/sage_trac/ticket/1075 The purpose of the patch is to fix the lack of substitution in the following code snippet (it also has other ramifications in similar contexts): sage: R.<x,y>=ZZ[] sage: (x/y).subs({x:1}) x/y
The patch is to add a __hash__ method to the FractionFieldElement class to make fractions with denominator 1 hash the same as the numerator. Thus, this patch makes == and __hash__ agree for the case of embedding a ring into it's fraction field. For some reason, which is a mystery to me, that code snippet works as expected if you replace ZZ with QQ. I realize that behind the scenes that gives you an entirely different implementation (for the poly ring -- not the fractionfield), but I don't understand why the hash values somehow work out for the QQ case, but not the ZZ case. Note that '==' and __hash__ have been hashed (pardon the pun) at some length in the thread with this message: http://groups.google.com/group/sage-devel/msg/b3812493e9d2d2c8 thanks Joel --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
