quaternion-valued differential forms
I'm trying to define quaternion-valued differential forms in Sage. For example, take e0, e1, e2, e3 to be the quaternion generators and dx0, dx1, dx2, dx3 be the generators of the exterior algebra. So for example I'd like to be able to compute dX∧dX†, where dX=e0dx0+e1dx1+e2dx2+e3dx3, dX†=e0dx0−e1dx1−e2dx2−e3dx3.
Edit: I tried taking a tensor product between an exterior algebra and a quaternion algebra
sage: ext_alg.<x0,x1,x2,x3> = ExteriorAlgebra(QQ)
sage: ext_alg in Algebras(QQ)
True
sage: quat_alg = QuaternionAlgebra(QQ,-1,-1)
sage: quat_alg in Algebras(QQ)
True
sage: tensor((ext_alg, quat_alg)) # this doesn't work!