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: "a robust specification theory for modal event clock automata"
  Abstract: In a series of recent work, we have introduced a general framework for quantitative reasoning in specification theories. The contribution of this paper is to show how this framework can be applied to yield a robust specification theory for timed specifications.

Connected through hyperedge HE-1 (induced by source paper "computing branching distances using quantitative games"):
  with members:
    - "a linear time branching time spectrum of behavioral specification theories"
    - "compositionality for quantitative specifications"

Connected through hyperedge HE-2 (induced by source paper "compositionality for quantitative specifications"):
  with members:
    - "refinement and difference for probabilistic automata"
    - "structural refinement for the modal nu calculus"
    - "hennessy milner logic with greatest fixed points as a complete behavioural specification theory"
    - "probabilistic modal mu calculus with independent product"
    - "weighted modal transition systems"
    - "a parametric counterexample refinement approach for robust timed specifications"

Connected through hyperedge HE-3 (induced by source paper "modal specifications for probabilistic timed systems"):
  with members:
    - "revisiting timed specification theories a linear time perspective"

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)