  In this paper, we develop a formalism describing in a relativistic way a
system which consists of a classical and a quantum part being coupled. The
formalism models one particle with spin 1/2 and it is a possible relativistic
extension of the Event-Enhanced Quantum Theory. We postulate a covariant
algorithm which plays the role of the standard reduction postulate in
non-relativistic quantum mechanics. Furthermore, we present an algorithm to
simulate detections of the particle.
