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: "copyless cost register automata structure expressiveness and closure properties"
  Abstract: Cost register automata (CRA) and its subclass, copyless CRA, were recently proposed by Alur et al. as a new model for computing functions over strings. We study some structural properties, expressiveness, and closure properties of copyless CRA. We show that copyless CRA are strictly less expressive than weighted automata and are not closed under reverse operation. To find a better class we impose restrictions on copyless CRA, which ends successfully with a new robust computational model that is closed under reverse and other extensions.

Connected through hyperedge HE-1 (induced by source paper "pumping lemmas for weighted automata"):
  with members:
    - "a robust class of linear recurrence sequences"
    - "weak cost register automata are still powerful"
    - "descriptive complexity for counting complexity classes"
    - "on the positivity problem for simple linear recurrence sequences"
    - "decision problems for additive regular functions"
    - "ultimate positivity is decidable for simple linear recurrence sequences"
    - "deciding unambiguity and sequentiality from a finitely ambiguous max plus automaton"

Connected through hyperedge HE-2 (induced by source paper "on polynomial recursive sequences"):
  with members:
    - "the parikh property for weighted context free grammars"

Connected through hyperedge HE-3 (induced by source paper "aperiodic weighted automata and weighted first order logic"):
  with members:
    - "pumping lemmas for weighted automata"
    - "weighted automata and logics for infinite nested words"
    - "multi weighted automata and mso logic"
    - "expressiveness and closure properties for quantitative languages"
    - "deciding unambiguity and sequentiality from a finitely ambiguous max plus automaton"

Connected through hyperedge HE-4 (induced by source paper "bidirectional nested weighted automata"):
  with members:
    - "nested weighted limit average automata of bounded width"
    - "quantitative automata under probabilistic semantics"
    - "nested weighted automata"
    - "expressiveness and closure properties for quantitative languages"

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.FL(Formal Languages and Automata Theory)