Merge strategy DFP
This merge strategy implements the algorithm originally described in the paper "Directed model checking with distance-preserving abstractions" by Draeger, Finkbeiner and Podelski (SPIN 2006), adapted to planning in the following paper:
Silvan Sievers, Martin Wehrle, and Malte Helmert.
Generalized Label Reduction for Merge-and-Shrink Heuristics.
In Proceedings of the 28th AAAI Conference on Artificial Intelligence (AAAI 2014), pp. 2358-2366. AAAI Press 2014.
merge_dfp()
Linear merge strategies
This merge strategy implements several linear merge orders, which are described in the paper:
Malte Helmert, Patrik Haslum and Joerg Hoffmann..
Flexible Abstraction Heuristics for Optimal Sequential Planning..
In Proceedings of the Seventeenth International Conference on Automated Planning and Scheduling (ICAPS 2007), pp. 176-183. 2007.
merge_linear(variable_order=CG_GOAL_LEVEL)
variable_order ({CG_GOAL_LEVEL, CG_GOAL_RANDOM, GOAL_CG_LEVEL, RANDOM, LEVEL, REVERSE_LEVEL}): the order in which atomic transition systems are merged