BERGMANN, who opened the session, proposed that the following topics should be discussed together in this session: the integration of the partial differential equations of general relativity, the properties of their solutions, the invariants of the theory, and various topological problems.
LICHNEROWICZ was the first speaker. For details, including those of notation and terminology, the reader is referred to his book, Théories Relativistes de la Gravitation et de l'Électromagnétisme, Paris, 1955.
