BibTeX

@article{gabbay/reyle:1994,
  author = {Gabbay, Dov and Reyle, Uwe},
  title = {N-{PROLOG}: {A}n Extension of {PROLOG} with Hypothetical Implications},
  journal = {Journal of Logic Programming},
  year = {1994},
  volume = {4},
  pages = {319-355}
}