I am having an error whenever I attempt to construct a homomorphism
- from a Laurent polynomial ring - to a Laurent polynomial ring in more than one variable. Ex (SageMath Cloud, 5/12/15): R.<a>=LaurentPolynomialRing(ZZ) S.<b,c>=LaurentPolynomialRing(ZZ) phi=Hom(R,S)([b]) TypeError: images do not define a valid homomorphism Additional data: - An identical error occurs with the variant syntax R.hom([b]). - An identical error occurs when trying to construct the identity homomorphism on LaurentPolynomialRing(ZZ,'x,y'). - There is no error if the domain is replaced by PolynomialRing(ZZ,'a'). - There is no error if the image of 'a' is 1. - There is no error if the codomain is replaced by its own fraction field. - There is no error if the second generator 'c' is removed from the codomain. It appears that Sage is incorrectly determining that the reciprocal of the image of the generator(s) is not in the codomain, and raising an error. (Link <http://ask.sagemath.org/question/26813/typeerror-for-hom-between-multivariate-laurent-polynomial-rings/> to identical question on ask.sagemath.org) -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
