Weyl-Wigner-Moyal formulation of a Dirac quantized constrained system
  An extension of the Weyl-Wigner-Moyal formulation of quantum mechanics suitable for a Dirac quantized constrained system is proposed. In this formulation, quantum observables are described by equivalent classes of Weyl symbols. The Weyl product of these equivalent classes is defined. The new Moyal bracket is shown to be compatible with the Dirac bracket for constrained systems. 
Domingo J. Louis-Martinez (University of British Columbia)