Generally covariant field theories have associated with them, in the canonical formalism, a series of primary and secondary constraints. For a large class of these theories it is proven that there exists a transformation which will reduce the primary constraints to the form of a set of momenta equal to zero. The transformation which accomplishes this reduction is exhibited explicity for the case of general relativity.

• Received 28 March 1958

DOI:https://doi.org/10.1103/PhysRev.111.965