Constraint Equational Logic Programming and Resource{based Partial Order Planning

Nowadays planning systems are usually based on partially order sets of actions as these sets specify necessary ordering constraints but do not commit otherwise. While computing these sets one usually maintains lists of links in order to detect potential threats. As shown in this paper these maintenance operations are unneccessary if the preconditions as well as eeects of actions are modelled as resources instead of properties. Moreover, whereas all partial order planning systems that we are aware of are non{deductive and non-declarative this new view allows to specify a purely deductive partial order planner as a simple constrained equational logic program.