Second quantization of field systems on a Grassmann Algebra dual string with internal spin

A study is made of the classical mechanics and canonical quantization of systems with commuting and anticommuting variables (mixed systems). Boson and fermion dual strings with internal spin are second quantized. A representation of the propagator of the spin string in terms of a path integral with respect to commuting and anticommuting variables is considered and a rule for matching such integrals is obtained.