# Revision history [back]

### Using polynomial over matrices

Things goes wrong when I try to define polynomial ring over a matrix algebra. When I type

A = MatrixSpace(QQ, 2)
PA.<x> = PolynomialRing(A)
x


I obtain the following error :

AttributeError: 'MatrixSpace_generic' object has no attribute 'is_atomic_repr'


Of course, I could use matrices over polynomial rings, but I would loss generality of the code... Do you have any idea ?