@article{gradedcausationanddefaults,
  title = {Graded Causation and Defaults},
  author = {Joseph Y. Halpern and Christopher Hitchcock},
  year = {2013},
  eprint = {1309.1226},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1309.1226v1},
}