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: "borel hierarchy and omega context free languages"
  Abstract: We give in this paper additional answers to questions of Lescow and Thomas [Logical Specifications of Infinite Computations, In:"A Decade of Concurrency", Springer LNCS 803 (1994), 583-621], proving new topological properties of omega context free languages : there exist some omega-CFL which are non Borel sets. And one cannot decide whether an omega-CFL is a Borel set. We give also an answer to questions of Niwinski and Simonnet about omega powers of finitary languages, giving an example of a finitary context free language L such that L^omega is not a Borel set. Then we prove some recursive analogues to preceding properties: in particular one cannot decide whether an omega-CFL is an arithmetical set.

Connected through hyperedge HE-1 (induced by source paper "the determinacy of context free games"):
  with members:
    - "highly undecidable problems for infinite computations"
    - "the complexity of infinite computations in models of set theory"
    - "borel ranks and wadge degrees of context free omega languages"

Connected through hyperedge HE-2 (induced by source paper "highly undecidable problems for infinite computations"):
  with members:
    - "on recognizable languages of infinite pictures"
    - "on the topological complexity of infinitary rational relations"
    - "highly undecidable problems about recognizability by tiling systems"
    - "undecidable problems about timed automata"
    - "borel ranks and wadge degrees of context free omega languages"

Connected through hyperedge HE-3 (induced by source paper "the complexity of infinite computations in models of set theory"):
  with members:
    - "highly undecidable problems for infinite computations"
    - "on recognizable languages of infinite pictures"
    - "topological complexity of context free omega languages a survey"
    - "highly undecidable problems about recognizability by tiling systems"
    - "borel ranks and wadge degrees of context free omega languages"

Connected through hyperedge HE-4 (induced by source paper "topological complexity of context free omega languages a survey"):
  with members:
    - "on omega context free languages which are borel sets of infinite rank"
    - "an effective extension of the wagner hierarchy to blind counter automata"
    - "on winning conditions of high borel complexity in pushdown games"
    - "wadge degrees of infinitary rational relations"
    - "the complexity of games on higher order pushdown automata"
    - "borel ranks and wadge degrees of context free omega languages"

Connected through hyperedge HE-5 (induced by source paper "on infinite real trace rational languages of maximum topological complexity"):
  with members:
    - "on recognizable languages of infinite pictures"
    - "on the topological complexity of infinitary rational relations"

Connected through hyperedge HE-6 (induced by source paper "on the length of the wadge hierarchy of omega context free languages"):
  with members:
    - "on omega context free languages which are borel sets of infinite rank"
    - "an effective extension of the wagner hierarchy to blind counter automata"

Connected through hyperedge HE-7 (induced by source paper "highly undecidable problems about recognizability by tiling systems"):
  with members:
    - "highly undecidable problems for infinite computations"
    - "on recognizable languages of infinite pictures"

Connected through hyperedge HE-8 (induced by source paper "the wadge hierarchy of deterministic tree languages"):
  with members:
    - "borel ranks and wadge degrees of context free omega languages"

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)