Relational Bayesian Networks
  A new method is developed to represent probabilistic relations on multiple
random events. Where previously knowledge bases containing probabilistic rules
were used for this purpose, here a probability distribution over the relations
is directly represented by a Bayesian network. By using a powerful way of
specifying conditional probability distributions in these networks, the
resulting formalism is more expressive than the previous ones. Particularly, it
provides for constraints on equalities of events, and it allows to define
complex, nested combination functions.
