Generic solutions for some integrable lattice equations
  We derive the expressions for $\psi$-functions and generic solutions of lattice principal chiral equations, lattice KP hierarchy and hierarchy including lattice N-wave type equations. $\tau$-function of $n$ free fermions plays fundamental role in this context. Miwa's coordinates in our case appear as the lattice parameters. 
L.V. Bogdanov (International Institute for Nonlinear Sciences, the   Russian branch)