Revealing Hidden Preconditions and Effects of Compound HTN Planning Tasks - A Complexity Analysis

Date

2021-05-18

Authors

Olz, Conny
Biundo, Susanne
Bercher, Pascal

Journal Title

Journal ISSN

Volume Title

Publisher

The AAAI Press

Abstract

In Hierarchical Task Network (HTN) planning, compound tasks need to be refined into executable (primitive) action sequences. In contrast to their primitive counterparts, compound tasks do not show preconditions or effects. Thus, their implications on the states in which they are applied are not explicitly known: they are "hidden" in and depending on the decomposition structure. We formalize several kinds of preconditions and effects that can be inferred for compound tasks in totally ordered HTN domains. As relevant special case we introduce a problem relaxation which admits reasoning about preconditions and effects in polynomial time. We provide procedures for doing so, thereby extending previous work, which could only deal with acyclic models. We prove our procedures to be correct and complete for any totally ordered input domain. The results are embedded into an encompassing complexity analysis of the inference of preconditions and effects of compound tasks, an investigation that has not been made so far.

Description

Keywords

Citation

Olz, C., Biundo, S., & Bercher, P. (2021). Revealing Hidden Preconditions and Effects of Compound HTN Planning Tasks – A Complexity Analysis. Proceedings of the AAAI Conference on Artificial Intelligence, 35(13), 11903-11912. https://doi.org/10.1609/aaai.v35i13.17414

Source

Type

Conference paper

Book Title

Entity type

Access Statement

Open Access

License Rights

Restricted until