- paper abstract
On hierarchical task networks
Andreas Herzig, Laurent Perrussel, Zhanhao Xiao
In planning based on hierarchical task networks (HTN), plans
are generated by refining high-level actions (`compound tasks') into lower-level
actions, until primitive actions are obtained that can be sent to execution.
While a primitive action is defined by its precondition and
e.ects, a high-level action is defined by zero, one or several methods:
sets of (high-level or primitive) actions decomposing it together with a
constraint. We give a semantics of HTNs in terms of dynamic logic with
program inclusion. We propose postulates guaranteeing soundness and
completeness of action refinement. We also show that hybrid planning
can be analysed in the same dynamic logic framework.