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: "a model theoretic semantics for defeasible logic"
  Abstract: Defeasible logic is an efficient logic for defeasible reasoning. It is defined through a proof theory and, until now, has had no model theory. In this paper a model-theoretic semantics is given for defeasible logic. The logic is sound and complete with respect to the semantics. We also briefly outline how this approach extends to a wide range of defeasible logics.

Connected through hyperedge HE-1 (induced by source paper "annotated defeasible logic"):
  with members:
    - "the rationale behind the concept of goal"
    - "relative expressiveness of defeasible logics"
    - "interdefinability of defeasible logic and logic programming under the well founded semantics"
    - "propositional defeasible logic has linear complexity"

Connected through hyperedge HE-2 (induced by source paper "extended rdf as a semantic foundation of rule markup languages"):
  with members:
    - "n3logic a logical framework for the world wide web"
    - "representation results for defeasible logic"

Connected through hyperedge HE-3 (induced by source paper "embedding defeasible logic into logic programming"):
  with members:
    - "propositional defeasible logic has linear complexity"
    - "representation results for defeasible logic"
    - "a flexible framework for defeasible logics"

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.LO(Logic in Computer Science)