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: "on the existence of stable models of non stratified logic programs"
  Abstract: This paper introduces a fundamental result, which is relevant for Answer Set programming, and planning. For the first time since the definition of the stable model semantics, the class of logic programs for which a stable model exists is given a syntactic characterization. This condition may have a practical importance both for defining new algorithms for checking consistency and computing answer sets, and for improving the existing systems. The approach of this paper is to introduce a new canonical form (to which any logic program can be reduced to), to focus the attention on cyclic dependencies. The technical result is then given in terms of programs in canonical form (canonical programs), without loss of generality. The result is based on identifying the cycles contained in the program, showing that stable models of the overall program are composed of stable models of suitable sub-programs, corresponding to the cycles, and on defining the Cycle Graph. Each vertex of this graph corresponds to one cycle, and each edge corresponds to onehandle, which is a literal containing an atom that, occurring in both cycles, actually determines a connection between them. In fact, the truth value of the handle in the cycle where it appears as the head of a rule, influences the truth value of the atoms of the cycle(s) where it occurs in the body. We can therefore introduce the concept of a handle path, connecting different cycles. If for every odd cycle we can find a handle path with certain properties, then the existence of stable model is guaranteed.

Connected through hyperedge HE-1 (induced by source paper "about epistemic negation and world views in epistemic logic programs"):
  with members:
    - "splitting epistemic logic programs"
    - "query answering in resource based answer set semantics"
    - "revisiting epistemic specifications"
    - "xsb extending prolog with tabled logic programming"
    - "normal forms for answer sets programming"
    - "transformation based bottom up computation of the well founded model"
    - "extremal problems in logic programming and stable model computation"

Connected through hyperedge HE-2 (induced by source paper "answering the why in answer set programming a survey of explanation approaches"):
  with members:
    - "achievements in answer set programming"
    - "enablers and inhibitors in causal justifications of logic programs"
    - "stepwise debugging of answer set programs"
    - "justifications for programs with disjunctive and causal choice rules"
    - "deriving conclusions from non monotonic cause effect relations"
    - "an integrated graphical user interface for debugging answer set programs"
    - "justifying answer sets using argumentation"
    - "asperix a first order forward chaining approach for answer set computing"

Connected through hyperedge HE-3 (induced by source paper "normal forms for answer sets programming"):
  with members:
    - "transformation based bottom up computation of the well founded model"
    - "stable models and an alternative logic programming paradigm"

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)