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: "structure preserving bisimilarity supporting an operational petri net semantics of ccsp"
  Abstract: In 1987 Ernst-Rudiger Olderog provided an operational Petri net semantics for a subset of CCSP, the union of Milner’s CCS and Hoare’s CSP. It assigns to each process term in the subset a labelled, safe place/transition net. To demonstrate the correctness of the approach, Olderog established agreement (1) with the standard interleaving semantics of CCSP up to strong bisimulation equivalence, and (2) with standard denotational interpretations of CCSP operators in terms of Petri nets up to a suitable semantic equivalence that fully respects the causal structure of nets. For the latter he employed a linear-time semantic equivalence, namely having the same causal nets.

Connected through hyperedge HE-1 (induced by source paper "ensuring liveness properties of distributed systems open problems"):
  with members:
    - "progress justness and fairness"
    - "reward testing equivalences for processes"
    - "justness a completeness criterion for capturing liveness properties"
    - "analysing mutual exclusion using process algebra with signals"
    - "lean and full congruence formats for recursion"
    - "ccs it s not fair fair schedulers cannot be implemented in ccs like languages even under progress and certain fairness assumptions"
    - "progress fairness and justness in process algebra"
    - "a process algebra for wireless mesh networks"

Connected through hyperedge HE-2 (induced by source paper "justness a completeness criterion for capturing liveness properties"):
  with members:
    - "progress justness and fairness"
    - "analysing mutual exclusion using process algebra with signals"
    - "ensuring liveness properties of distributed systems a research agenda"
    - "progress fairness and justness in process algebra"
    - "a process algebra for wireless mesh networks"
    - "a process algebra for wireless mesh networks used for modelling verifying and analysing aodv"
    - "on characterising distributability"
    - "on synchronous and asynchronous interaction in distributed systems"

Connected through hyperedge HE-3 (induced by source paper "ensuring liveness properties of distributed systems a research agenda"):
  with members:
    - "automated analysis of aodv using uppaal"
    - "a process algebra for wireless mesh networks"
    - "a process algebra for wireless mesh networks used for modelling verifying and analysing aodv"
    - "sequence numbers do not guarantee loop freedom aodv can yield routing loops"
    - "on characterising distributability"
    - "psi calculi a framework for mobile processes with nominal data and logic"
    - "branching bisimilarity with explicit divergence"

Connected through hyperedge HE-4 (induced by source paper "private names in non commutative logic"):
  with members:
    - "a deep inference system with a self dual binder which is complete for linear lambda calculus"
    - "a quasipolynomial cut elimination procedure in deep inference via atomic flows and threshold formulae"
    - "on the proof complexity of deep inference"
    - "a system of interaction and structure"
    - "a system of interaction and structure ii the need for deep inference"

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)