General Covariance and the "Problem of Time" in a Discrete Cosmology
  Identifying an appropriate set of ``observables'' is a nontrivial task for most approaches to quantum gravity. We describe how it may be accomplished in the context of a recently proposed family of stochastic (but classical) dynamical laws for causal sets. The underlying idea should work equally well in the quantum case. 
Graham Brightwell (London School of Economics), H. Fay Dowker and Joe   Henson (Queen Mary College, University of London), R...