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: "branching bisimilarity on normed bpa is exptime complete"
  Abstract: We put forward an exponential-time algorithm for deciding branching bisimilarity on normed BPA (Bacis Process Algebra) systems. The decidability of branching (or weak) bisimilarity on normed BPA was once a long standing open problem which was closed by Yuxi Fu. The EXPTIME-hardness is an inference of a slight modification of the reduction presented by Richard Mayr. Our result claims that this problem is EXPTIME-complete.

Connected through hyperedge HE-1 (induced by source paper "branching bisimilarity of normed bpa processes as a rational monoid"):
  with members:
    - "two lower bounds for bpa"
    - "a polynomial time algorithm for deciding branching bisimilarity on totally normed bpa"
    - "branching bisimilarity of normed bpa processes is in nexptime"
    - "branching bisimilarity checking for prs"
    - "bisimilarity on basic process algebra is in 2 exptime an explicit proof"
    - "bpa bisimilarity is exptime hard"

Connected through hyperedge HE-2 (induced by source paper "branching bisimilarity of normed bpa processes is in nexptime"):
  with members:
    - "a polynomial time algorithm for deciding branching bisimilarity on totally normed bpa"
    - "branching bisimilarity checking for prs"
    - "bisimilarity on basic process algebra is in 2 exptime an explicit proof"
    - "bpa bisimilarity is exptime hard"

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)