To whom it may concern, there is plural: http://www.singular.uni-kl.de/Manual/latest/sing_349.htm
which is shipped with SAGE (though, the interface hasn't been worked on) sage: singular.lib('ncalg.lib') sage: a = singular.makeUsl2() sage: W = singular.ring(0,'(x,d)','dp') sage: singular.Weyl() `sage2` sage: S = a + W sage: singular.set_ring(S) sage: S // characteristic : 0 // number of vars : 5 // block 1 : ordering dp // : names e f h // block 2 : ordering dp // : names x d // block 3 : ordering C // noncommutative relations: // fe=e*f-h // he=e*h+2*e // hf=f*h-2*f // dx=x*d+1 or in terms of SINGULAR/PLURAL directly: LIB "ncalg.lib"; def a = makeUsl2(); // U(sl_2) in e,f,h presentation ring W = 0,(x,d),dp; Weyl(); // 1st Weyl algebra in x,d def S = a+W; setring S; S; ==> // characteristic : 0 ==> // number of vars : 5 ==> // block 1 : ordering dp ==> // : names e f h ==> // block 2 : ordering dp ==> // : names x d ==> // block 3 : ordering C ==> // noncommutative relations: ==> // fe=ef-h ==> // he=eh+2e ==> // hf=fh-2f ==> // dx=xd+1 Martin PS: I don't know much about non-commutative algebra, so I wouldn't know if your favorite ring is supported by PLURAL. -- name: Martin Albrecht _pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 _www: http://www.informatik.uni-bremen.de/~malb _jab: [EMAIL PROTECTED] --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---