Equivalence of the perturbation theories of Hori and Deprit

A comparison is made between the perturbation theories of Hori and Deprit which are based on the use of Poisson brackets. General recurrence formulae are presented for Hori's theory which are analogous to those in Deprit's theory. Explicit relations between the determining functions for the two theories are indicated through the sixth order, these results having been obtained by a novel computer program. A general argument for the equivalence of the theories to all orders is given.