  We investigate dynamical symmetry breaking of the Gross-Neveu model in the
light-front formalism without introducing auxiliary fields. While this system
cannot have zero-mode constraints, we find that a nontrivial solution to the
constraint on nondynamical spinor fields is responsible for symmetry breaking.
The fermionic constraint is solved by systematic 1/$N$ expansion using the
boson expansion method as a technique. Carefully treating the infrared
divergence, we obtain a nonzero vacuum expectation value for fermion condensate
in the leading order. We derive the 't Hooft equation including the effect of
condensation, and determine the Hamiltonian consistently with the equation of
motion.
