Causes and Explanations in the Structural-Model Approach: Tractable
  Cases
  In this paper, we continue our research on the algorithmic aspects of Halpern
and Pearl's causes and explanations in the structural-model approach. To this
end, we present new characterizations of weak causes for certain classes of
causal models, which show that under suitable restrictions deciding causes and
explanations is tractable. To our knowledge, these are the first explicit
tractability results for the structural-model approach.
