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: "better abstractions for timed automata"
  Abstract: We study the reachability problem for timed automata. A standard solution to this problem involves computing a search tree whose nodes are abstractions of zones. These abstractions preserve underlying simulation relations on the state space of the automaton. For both effectiveness and efficiency reasons, they are parameterized by the maximal lower and upper bounds (LU-bounds) occurring in the guards of the automaton.One such abstraction is the a ź L U abstraction defined by Behrmann et al. Since this abstraction can potentially yield non-convex sets, it has not been used in implementations. Firstly, we prove that a ź L U abstraction is the coarsest abstraction with respect to LU-bounds that is sound and complete for reachability. Secondly, we provide an efficient technique to use the a ź L U abstraction to solve the reachability problem.

Connected through hyperedge HE-1 (induced by source paper "automated synthesis of local time requirement for service composition"):
  with members:
    - "abstraction refinement algorithms for timed automata"
    - "revisiting reachability in timed automata"
    - "the parma polyhedra library toward a complete set of numerical abstractions for the analysis and verification of hardware and software systems"

Connected through hyperedge HE-2 (induced by source paper "fast algorithms for handling diagonal constraints in timed automata"):
  with members:
    - "reachability in timed automata with diagonal constraints"
    - "revisiting timed logics with automata modalities"
    - "symbolic optimal reachability in weighted timed automata"
    - "improving search order for reachability testing in timed automata"
    - "lazy abstractions for timed automata"

Connected through hyperedge HE-3 (induced by source paper "parametric timed model checking for guaranteeing timed opacity"):
  with members:
    - "what s decidable about parametric timed automata"
    - "eliminating timing side channel leaks using program repair"
    - "adversarial symbolic execution for detecting concurrency related cache timing leaks"
    - "canal a cache timing analysis framework via llvm transformation"
    - "control and synthesis of non interferent timed systems"

Connected through hyperedge HE-4 (induced by source paper "revisiting local time semantics for networks of timed automata"):
  with members:
    - "fast algorithms for handling diagonal constraints in timed automata"
    - "abstract interpretation with unfoldings"

Connected through hyperedge HE-5 (induced by source paper "symbolic optimal reachability in weighted timed automata"):
  with members:
    - "improving search order for reachability testing in timed automata"
    - "fast detection of cycles in timed automata"
    - "using non convex approximations for efficient analysis of timed automata"

Connected through hyperedge HE-6 (induced by source paper "reducing clocks in timed automata while preserving bisimulation"):
  with members:
    - "a unifying approach to decide relations for timed automata and their game characterization"
    - "undecidable problems about timed automata"
    - "small maximal independent sets and faster exact graph coloring"

Connected through hyperedge HE-7 (induced by source paper "lazy abstractions for timed automata"):
  with members:
    - "using non convex approximations for efficient analysis of timed automata"

Connected through hyperedge HE-8 (induced by source paper "coarse abstractions make zeno behaviours difficult to detect"):
  with members:
    - "using non convex approximations for efficient analysis of timed 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)