Hi! A little addendum:
> For a similar reason, neither f nor g are elements of R. I would agree that it is a little confusing that something is equal to an element of a polynomial ring but is not an element of that ring, or in pure form: sage: R = QQ['x','y'] sage: R1.<x>=QQ[] sage: R2.<y>=QQ[] sage: x in R False sage: x == R.gen(0) True This is at least inconsistent, because for rational numbers that happen to be integers, the containment is answered in a different way: sage: (1/1).parent() Rational Field sage: (1/1).parent() == ZZ False sage: 1/1 in ZZ True So, although 1/1 is given as an element of the rationals, it is recognized as an element of the integers. But why is the generator x of a univariate polynomial ring not recognized as an element of a bivariate polynomial ring in x and y? Question to the developers: Is this perhaps due to the following (a bug in the coercion system?): sage: R._has_coerce_map_from(R) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/SimonKing/.sage/temp/sage.math.washington.edu /5548/ _home_SimonKing__sage_init_sage_0.py in <module>() TypeError: 'dict' object is not callable This happens on sage.math with sage-3.4.2. Shall I open a ticket? Cheers, Simon --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
