  This work is a continuation and extension of the note published in the
Russian Math Surveys 1997 n 6. For any pair of solutions of the spectral
problem for the second order selfadjoint real Schrodinger Operator on the graph
their Symplectic Wronskian is a 1-cycle in the graph. This is a vector-valued
symplectic 2-form on the space of solutions. This construction was applied to
the Scattering Theory on the graphs with finite number of tails. The asymptotic
values of solutions is a Lagrangian Plane of half dimension. This property
determines all unitary properties of Scattering Matrix, which is also
symmetric. All higher order discrete operators and operators on higher
dimensional simplicial complexes are included in this scheme. Nonlinear analog
of that was invented by the present author in collaboration with A.S.Schwarz.
