More about exactly massless quarks on the lattice
  In a previous publication [hep-lat/9707022] I showed that the fermion determinant for strictly massless quarks can be written on the lattice as $\det D$, where $D$ is a certain finite square matrix explicitly constructed from the lattice gauge fields. Here I show that $D$ obeys the Ginsparg-Wilson relation $D\gamma_5 D = D\gamma_5 +\gamma_5 D$. 
H. Neuberger (Rutgers)