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: "interactive verification of markov chains two distributed protocol case studies"
  Abstract: Probabilistic model checkers like PRISM only check probabilistic systems of a ﬁxed size. To guar-antee the desired properties for an arbitrary size, mathematical analysis is necessary. We show fortwo case studies how this can be done in the interactive proof assistant Isabelle/HOL. The ﬁrst casestudy is a detailed description of how we veriﬁed properties of the ZeroConf protocol, a decentral ad-dress allocation protocol. The second case study shows the more involved veriﬁcation of anonymityproperties of the Crowds protocol, an anonymizing protocol.

Connected through hyperedge HE-1 (induced by source paper "formal verification of cyber physical systems using theorem proving invited paper"):
  with members:
    - "formal analysis of robotic cell injection systems using theorem proving"
    - "qwire practice formal verification of quantum circuits in coq"
    - "formal analysis of linear control systems using theorem proving"
    - "formal analysis of continuous time systems using fourier transform"
    - "formalization of transform methods using hol light"
    - "towards formal fault tree analysis using theorem proving"
    - "a verified compiler for probability density functions"
    - "towards the formal reliability analysis of oil and gas pipelines"

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)