Contents
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.