A landmark factory specification is either a newly created instance or a landmark factory that has been defined previously. This page describes how one can specify a new landmark factory instance. For re-using landmark factories, see Landmark Predefinitions.

This plugin type can be predefined using --landmarks.

Exhaustive Landmarks

Exhaustively checks for each fact if it is a landmark.This check is done using relaxed planning.

lm_exhaust(only_causal_landmarks=false)

• only_causal_landmarks (bool): keep only causal landmarks

Language features supported:

• conditional_effects: ignored, i.e. not supported

h^m Landmarks

The landmark generation method introduced by Keyder, Richter & Helmert (ECAI 2010).

lm_hm(m=2, conjunctive_landmarks=true, use_orders=true)

• m (int): subset size (if unsure, use the default of 2)

• conjunctive_landmarks (bool): keep conjunctive landmarks

• use_orders (bool): use orders between landmarks

Merged Landmarks

Merges the landmarks and orderings from the parameter landmarks

lm_merged(lm_factories)

• lm_factories (list of LandmarkFactory):

Precedence: Fact landmarks take precedence over disjunctive landmarks, orderings take precedence in the usual manner (gn > nat > reas > o_reas).

Note: Does not currently support conjunctive landmarks

Language features supported:

• conditional_effects: supported if all components support them

HPS Orders

Adds reasonable orders and obedient reasonable orders described in the following paper

• Jörg Hoffmann, Julie Porteous and Laura Sebastia.
  Ordered Landmarks in Planning.
  Journal of Artificial Intelligence Research 22:215-278. 2004.

lm_reasonable_orders_hps(lm_factory)

• lm_factory (LandmarkFactory):

Language features supported:

• conditional_effects: supported if subcomponent supports them

RHW Landmarks

The landmark generation method introduced by Richter, Helmert and Westphal (AAAI 2008).

lm_rhw(disjunctive_landmarks=true, use_orders=true, only_causal_landmarks=false)

• disjunctive_landmarks (bool): keep disjunctive landmarks

• use_orders (bool): use orders between landmarks

• only_causal_landmarks (bool): keep only causal landmarks

Language features supported:

• conditional_effects: supported

Zhu/Givan Landmarks

The landmark generation method introduced by Zhu & Givan (ICAPS 2003 Doctoral Consortium).

lm_zg(use_orders=true)

• use_orders (bool): use orders between landmarks

Language features supported:

• conditional_effects: We think they are supported, but this is not 100% sure.

moin code generated by txt2tags 2.6 (http://txt2tags.org) cmdline: txt2tags