  We derive a canonical analysis of a double null 2+2 Hamiltonian description
of General Relativity in terms of complex self-dual 2-forms and the associated
SO(3) connection variables. The algebra of first class constraints is obtained
and forms a Lie algebra that consists of two constraints that generate
diffeomorphisms in the two surface, a constraint that generates diffeomorphisms
along the null generators and a constraint that generates self-dual spin and
boost transformations.
