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: "reachability analysis of communicating pushdown systems"
  Abstract: The reachability analysis of recursive programs that communicate#N#asynchronously over reliable FIFO channels calls for restrictions to ensure#N#decidability. Our first result characterizes communication topologies with a#N#decidable reachability problem restricted to eager runs (i.e., runs where#N#messages are either received immediately after being sent, or never received).#N#The problem is EXPTIME-complete in the decidable case. The second result is a#N#doubly exponential time algorithm for bounded context analysis in this setting,#N#together with a matching lower bound. Both results extend and improve previous#N#work from La Torre et al.

Connected through hyperedge HE-1 (induced by source paper "timed basic parallel processes"):
  with members:
    - "effective definability of the reachability relation in timed automata"
    - "decidability of timed communicating automata"
    - "universal safety for timed petri nets is pspace complete"
    - "reachability in two clock timed automata is pspace complete"
    - "a faster algorithm for solving one clock priced timed games"
    - "reachability of communicating timed processes"
    - "reachability time games on timed automata"
    - "alternating timed automata"

Connected through hyperedge HE-2 (induced by source paper "on reachability for unidirectional channel systems extended with regular tests"):
  with members:
    - "complexity hierarchies beyond elementary"
    - "generalized post embedding problems"
    - "the parametric ordinal recursive complexity of post embedding problems"
    - "graph logics with rational relations"
    - "the power of well structured systems"
    - "cutting through regular post embedding problems"
    - "reachability of communicating timed processes"
    - "multiply recursive upper bounds with higman s lemma"

Connected through hyperedge HE-3 (induced by source paper "reachability analysis of reversal bounded automata on series parallel graphs"):
  with members:
    - "a perfect model for bounded verification"

Connected through hyperedge HE-4 (induced by source paper "decidable models of recursive asynchronous concurrency"):
  with members:
    - "complexity hierarchies beyond elementary"
    - "the reachability problem for vector addition systems with a stack is not elementary"
    - "queue dispatch asynchronous systems"
    - "on selective unboundedness of vass"

Connected through hyperedge HE-5 (induced by source paper "on the path width of integer linear programming"):
  with members:
    - "model checking of ordered multi pushdown automata"
    - "a bi directional refinement algorithm for the calculus of co inductive constructions"
    - "a perfect model for bounded verification"

Connected through hyperedge HE-6 (induced by source paper "zenoness for timed pushdown automata"):
  with members:
    - "a bi directional refinement algorithm for the calculus of co inductive constructions"
    - "efficient emptiness check for timed b uchi automata extended version"
    - "pushdown timed automata a binary reachability characterization and safety verification"

Connected through hyperedge HE-7 (induced by source paper "zenoness for timed pushdown automata"):
  with members:
    - "a bi directional refinement algorithm for the calculus of co inductive constructions"
    - "efficient emptiness check for timed b uchi automata extended version"
    - "pushdown timed automata a binary reachability characterization and safety verification"

Connected through hyperedge HE-8 (induced by source paper "saturation of concurrent collapsible pushdown systems"):
  with members:
    - "model checking of ordered multi pushdown automata"

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)