e
airport: the oldest planning problem in AI</a>" by
<a href="http://www.cs.utexas.edu/users/vl">Vladimir Lifschitz</a>,
Norman McCain, Emilio Remolina and
<a href="http://www.mrg.dist.unige.it/~tac/">Armando Tacchella</a> (in
<i>Logic-Based Artificial Intelligence</i>, 2000, pp.&nbsp;147-165),
adapted to the syntax of CCalc Version 2: the
<a href="airport/airport-domain">domain</a> and the
<a href="airport/airport-problem">problem</a>
 <li> From the paper
"<a href="http://www.cs.utexas.edu/users/vl/papers/