Trouble with CDGA's with One Generator

edit

Hi all, I've been using the functions associated with the GCAlgebra class to compute some minimal models for given cohomology algebras. It works fine whenever my cohomology algebra has 2 or more generators, but I can't get it to accept a single generator. I am trying, for example:

D.<x> = GradedCommutativeAlgebra(QQ, degrees = (2,))
d = D.differential({x:0,})
D = D.cdg_algebra(d)
I = D.ideal(x^3)
R = D.quotient(I)

It always fails on the quotient, the objection is that

   1324                               'homomorphisms of graded commutative '
   1325                               'algebras have only been implemented '
   1326                               'when the base rings are the same' "

I don't get it, pretty printing all objects shows they are all over the rational field. I did figure out that you need a comma to define a single-element tuple otherwise you get "not iterable" errors, but I think that's solved now. Any ideas?

To contrast, something like this runs fine:

D.<x,y> = GradedCommutativeAlgebra(QQ, degrees = (2,2))
d = D.differential({x:0, y:0})
D = D.cdg_algebra(d)
I = D.ideal([x^2-y^2,x*y,x^3,y^3])
R = D.quotient(I)

Note: it doesn't help to change D.ideal(x^3) to D.ideal([x^3]) or D.ideal([x^3,])... I thought maybe it expected a tuple. I've also seen examples where things like ideal(x^3) are written, so that shouldn't be an issue.

Thanks, Russ