@inproceedings{Simon10widening,
  author = {Axel Simon and Liqian Chen},
  title = {Simple and Precise Widenings for H-Polyhedra},
  booktitle = {8th Asian Symposium on Programming Languages and Systems (APLAS 2010)},
  editor = {K. Ueda},
  month = {November 28--December 1},
  year = {2010},
  pages = {139--155},
  series = {LNCS},
  volume = {6461},
  publisher = {Springer},
  address = {Shanghai, China},
}