additive-ijcai.ps">Describing
additive fluents in action language C+</a>" by
<a href="http://www.cs.utexas.edu/users/appsmurf">Joohyung Lee</a> and
<a href="http://www.cs.utexas.edu/users/vl">Vladimir Lifschitz</a>
(in <i>Proc.&nbsp;IJCAI-03</i>,  2003, pp.&nbsp;1079-1084):
 <ul>
   <li>Buying and Selling (Section 6): <a href="additive/buying">domain</a>
       and <a href="additive/buying-test">example</a>
   <li>Spacecraft Integer (Section 7): <a href="additive/spacecraft">domain</a>
       and <a href="a