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LAMA-FF synergy
If the FF heuristic should be used (for its estimates or its preferred operators) and we want to use preferred operators of the landmark count heuristic, we can exploit synergy effects by using the LAMA-FF synergy. This synergy can only be used via Predefinition (see Predefinitions), for example: "hlm,hff=lm_ff_syn(...)"
lm_ff_syn(lm_graph, admissible=false, optimal=false, alm=true, lpsolver=CPLEX, cost_type=NORMAL, transform=<none>)
lm_graph (LandmarkGraph):
admissible (bool): get admissible estimate
optimal (bool): optimal cost sharing
alm (bool): use action landmarks
lpsolver ({CLP, CPLEX, GUROBI}): external solver that should be used to solve linear programs
CLP: default LP solver shipped with the COIN library
CPLEX: commercial solver by IBM
GUROBI: commercial solver
cost_type ({NORMAL, ONE, PLUSONE}): Operator cost adjustment type. No matter what this setting is, axioms will always be considered as actions of cost 0 by the heuristics that treat axioms as actions.
NORMAL: all actions are accounted for with their real cost
ONE: all actions are accounted for as unit cost
PLUSONE: all actions are accounted for as their real cost + 1 (except if all actions have original cost 1, in which case cost 1 is used). This is the behaviour known for the heuristics of the LAMA planner. This is intended to be used by the heuristics, not search engines, but is supported for both.
transform (AbstractTask): Optional task transformation for the heuristic. Currently only adapt_costs is available.
Note: to use an LP solver, you must build the planner with USE_LP=1. See LPBuildInstructions.