@inproceedings{BartheCK13,
  author    = {Gilles Barthe and
               Juan Manuel Crespo and
               C{\'e}sar Kunz},
  title     = {Beyond 2-safety: asymmetric product programs for relational program verification},
  booktitle = {Symposium on Logical Foundations of Computer Science},
  year      = {2013},
  note      = {To appear}
}