If we eliminate P, Q, R from (22), the resulting equations are integrable with respect to t; thus Moa - M0a.
Hamiltonian theory is an important element of integrable systems, whether discrete, ordinary differential or partial differential equations.
They soon realized that the three body problem is not integrable, which means that no exact solution can ever be found.
We study the homoclinic orbits of the completely integrable discrete sine-Gordon.
A proof that homoclinic trajectories in the form of pinched tori imply monodromy in two degree of freedom integrable systems has also been given.