I ran into a problem where certain kinds of Laurent polynomials, defined through fractions, would be coercable while some other ones, defined by more or less the same fractions, would not be. It looks like a bug to me, but I figured I would run it by here first. Here's a concrete example of what I mean:
sage: R.<x> = LaurentPolynomialRing(ZZ) sage: p = (1-x^2)/(1-x) sage: p x + 1 sage: p.parent() Fraction Field of Univariate Polynomial Ring in x over Integer Ring sage: R(p) 1 + x sage: R(p).parent() Univariate Laurent Polynomial Ring in x over Integer Ring sage: q = (1-x^-2)/(1-x^-1) # I.e., replace x by x^-1 sage: q (x + 1)/x sage: q.parent() Fraction Field of Univariate Polynomial Ring in x over Integer Ring sage: R(q) TypeError: denominator must be a unit - Søren -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
