  A field theory with local transformations belonging to the quantum group
SU_q(n) is defined on a classical spacetime, with gauge potentials belonging to
a quantum Lie algebra. Gauge transformations are defined for the potentials
which lead to the appropriate quantum-group transformations for field strengths
and covariant derivatives, defined for all elements of SU_q(n) by means of the
adjoint action. This guarantees a non-trivial deformation. Gauge-invariant
commutation relations are identified.
