human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "the ff planning system fast plan generation through heuristic search"):
  Abstract: We describe and evaluate the algorithmic techniques that are used in the FF planning system. Like the HSP system, FF relies on forward state space search, using a heuristic that estimates goal distances by ignoring delete lists. Unlike HSP's heuristic, our method does not assume facts to be independent. We introduce a novel search strategy that combines hill-climbing with systematic search, and we show how other powerful heuristic information can be extracted and used to prune the search space. FF was the most successful automatic planner at the recent AIPS-2000 planning competition. We review the results of the competition, give data for other benchmark domains, and investigate the reasons for the runtime performance of FF compared to HSP.

Includes members:
  Member "on reasonable and forced goal orderings and their use in an agenda driven planning algorithm":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "planning based on classification by induction graph")
  Member "on the compilability and expressive power of propositional planning formalisms":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "efficient safe and probably approximately complete learning of action models")
  Member "efficient implementation of the plan graph in stan":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "marvin a heuristic search planner with online macro action learning")
  Member "the automatic inference of state invariants in tim":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "guarantees for sound abstractions for generalized planning extended paper")
  Member "when gravity fails local search topology":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "exploiting problem structure in combinatorial landscapes a case study on pure mathematics application")

Question: Please tell me which class the source paper belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.AI(Artificial Intelligence)