DO INTEGRABLE MAPPINGS HAVE THE PAINLEVE PROPERTY

We present an integrability criterion for discrete-time systems that is the equivalent of the Painleve property for systems of a continuous variable. It is based on the observation that for integrable mappings the singularities that may appear are confined, i.e., they do not propagate indefinitely when one iterates the mapping. Using this novel criterion we show that there exists a family of nonautonomous integrable mappings which includes the discrete Painleve equations P(I), recently derived in a model of two-dimensional quantum gravity, and P(II), obtained as a similarity reduction of the integrable modified Korteweg-de Vries lattice. These systems possess Lax pairs, a well-known integrability feature.