The condition for isoenergetic nondegeneracy for a Hamiltonian

is

which guarantees the Existence on every energy level surface of a set of invariant tori whose complement has a small Measure.

**References**

Tabor, M. *Chaos and Integrability in Nonlinear Dynamics: An Introduction.* New York: Wiley, pp. 113-114, 1989.

© 1996-9

1999-05-26