@inproceedings{ijcai2009p132,
  title     = {Bidirectional Answer Set Programs with Function Symbols},
  author    = {Eiter, Thomas and Simkus, Mantas},
  booktitle = {Proceedings of the Twenty-First International Joint Conference on
               Artificial Intelligence, {IJCAI-09}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Hiroaki Kitano},
  pages     = {765--770},
  year      = {2009},
  url       = {https://ijcai.org/proceedings/2009/132},
}