human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "efficient implementation of the plan graph in stan"
  Abstract: STAN is a Graphplan-based planner, so-called because it uses a variety of STate ANalysis techniques to enhance its performance. STAN competed in the AIPS-98 planning competition where it compared well with the other competitors in terms of speed, finding solutions fastest to many of the problems posed. Although the domain analysis techniques STAN exploits are an important factor in its overall performance, we believe that the speed at which STAN solved the competition problems is largely due to the implementation of its plan graph. The implementation is based on two insights: that many of the graph construction operations can be implemented as bit-level logical operations on bit vectors, and that the graph should not be explicitly constructed beyond the fix point. This paper describes the implementation of STAN's plan graph and provides experimental results which demonstrate the circumstances under which advantages can be obtained from using this implementation.

Connected through hyperedge HE-1 (induced by source paper "marvin a heuristic search planner with online macro action learning"):
  with members:
    - "the fast downward planning system"
    - "where ignoring delete lists works local search topology in planning benchmarks"
    - "macro ff improving ai planning with automatically learned macro operators"
    - "the deterministic part of ipc 4 an overview"
    - "the 3rd international planning competition results and analysis"
    - "the ff planning system fast plan generation through heuristic search"

Connected through hyperedge HE-2 (induced by source paper "planning through stochastic local search and temporal action graphs in lpg"):
  with members:
    - "pddl2 1 an extension to pddl for expressing temporal planning domains"
    - "the metric ff planning system translating ignoring delete lists to numeric state variables"
    - "the 3rd international planning competition results and analysis"
    - "the ff planning system fast plan generation through heuristic search"
    - "the automatic inference of state invariants in tim"
    - "flaw selection strategies for partial order planning"
    - "accelerating partial order planners some techniques for effective search control and pruning"

Connected through hyperedge HE-3 (induced by source paper "sapa a multi objective metric temporal planner"):
  with members:
    - "utility elicitation as a classification problem"
    - "pddl2 1 an extension to pddl for expressing temporal planning domains"
    - "vhpop versatile heuristic partial order planner"
    - "the 3rd international planning competition results and analysis"
    - "the ff planning system fast plan generation through heuristic search"
    - "the grt planning system backward heuristic construction in forward state space planning"

Connected through hyperedge HE-4 (induced by source paper "taming numbers and durations in the model checking integrated planning system"):
  with members:
    - "pddl2 1 an extension to pddl for expressing temporal planning domains"
    - "the ff planning system fast plan generation through heuristic search"
    - "on reasonable and forced goal orderings and their use in an agenda driven planning algorithm"
    - "obdd based universal planning for synchronized agents in non deterministic domains"
    - "computational aspects of reordering plans"
    - "the automatic inference of state invariants in tim"

Connected through hyperedge HE-5 (induced by source paper "altalt p online parallelization of plans with heuristic state search"):
  with members:
    - "the 3rd international planning competition results and analysis"
    - "computational aspects of reordering plans"

Connected through hyperedge HE-6 (induced by source paper "a critical assessment of benchmark comparison in planning"):
  with members:
    - "pddl2 1 an extension to pddl for expressing temporal planning domains"
    - "the ff planning system fast plan generation through heuristic search"
    - "flaw selection strategies for partial order planning"
    - "accelerating partial order planners some techniques for effective search control and pruning"

Connected through hyperedge HE-7 (induced by source paper "the ff planning system fast plan generation through heuristic search"):
  with members:
    - "on reasonable and forced goal orderings and their use in an agenda driven planning algorithm"
    - "on the compilability and expressive power of propositional planning formalisms"
    - "the automatic inference of state invariants in tim"
    - "when gravity fails local search topology"

Connected through hyperedge HE-8 (induced by source paper "the grt planning system backward heuristic construction in forward state space planning"):
  with members:
    - "the ff planning system fast plan generation through heuristic search"
    - "on reasonable and forced goal orderings and their use in an agenda driven planning algorithm"
    - "the automatic inference of state invariants in tim"
    - "total order and partial order planning a comparative analysis"

Question: Please tell me which class the center node 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)