BIRKHOFF

Program for Birkhoff-Gustavson normal form for $N$ degrees of freedom -- BIRKHOFF 1.2 A REDUCE program to calculate the Birkhoff-Gustavson normal form of a Hamiltonian system with $N$ degrees of freedom is presented. The potential of the system should be a polynomial in coordinates and momenta. The program enables the calculation of the approximate integrals of motion up to a given order in powers of coordinates and momenta.