Hi, I feel like this is a really dumb question, but how do you create a polynomial ring with elements that don't commute? I expected MPolynomialRing to have a parameter 'commutative', but I can't find any evidence of it.
So, as an alternative I tried a FreeAlgebra and it appears promising. But then I ran into what appears to be a bug: sage: P.<sk,sl,beta,ek,el>=FreeAlgebra(ZZ,5) sage: sk.subs(sk=sl) sk sage: sk.subs({sk:sl}) sk That is, the subs method simply won't subst anything. Can someone confirm that this is a bug that should be on trac (as opposed to me mis-understanding what a free algebra should do)? (Sadly, that was the entire point of my wanting a non-commutative poly ring was to later subst in matrices.) -- 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/ -~----------~----~----~----~------~----~------~--~---