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: "what are the fundamental structures of concurrency we still don t know"
  Abstract: Process algebra has been successful in many ways; but we don't yet see the lineaments of a fundamental theory. Some fleeting glimpses are sought from Petri Nets, physics and geometry.

Connected through hyperedge HE-1 (induced by source paper "bisimulation maps in presheaf categories"):
  with members:
    - "an intensionally fully abstract sheaf model for pi expanded version"
    - "what s in a game a theory of game models"
    - "on path based coalgebras and weak notions of bisimulation"
    - "innocent strategies as presheaves and interactive equivalences for ccs"
    - "hierarchical states in the compositional interchange format"

Connected through hyperedge HE-2 (induced by source paper "topological interpretation of interactive computation"):
  with members:
    - "an algebraic characterisation of concurrent composition"

Connected through hyperedge HE-3 (induced by source paper "information processes and games"):
  with members:
    - "retracing some paths in process algebra"
    - "a game semantics for generic polymorphism"
    - "games and full completeness for multiplicative linear logic"
    - "a structural approach to reversible computation"
    - "physical traces quantum vs classical information processing"

Connected through hyperedge HE-4 (induced by source paper "the name passing calculus"):
  with members:
    - "branching bisimilarity with explicit divergence"
    - "comparing the expressive power of the synchronous and asynchronous pi calculi"

Connected through hyperedge HE-5 (induced by source paper "intensionality definability and computation"):
  with members:
    - "information processes and games"
    - "axioms for definability and full completeness"
    - "games and full completeness for multiplicative linear logic"
    - "full abstraction for nominal general references"

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)