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: "on the expressibility of copyless cost register automata"
  Abstract: Cost register automata (CRA) were proposed by Alur et all as an alternative model for weighted automata. In hope of finding decidable subclasses of CRA, they proposed to restrict their model with the copyless restriction but nothing is really know about the structure or properties of this new computational model called copyless CRA. #R##N#In this paper we study the properties and expressiveness of copyless CRA. We propose a normal form for copyless CRA and we study the properties of a special group of registers (called stable registers). Furthermore, we find that copyless CRA do not have good closure properties since we show that they are not closed under reverse operation. Finally, we propose a subclass of copyless CRA and we show that this subclass is closed under regular-lookahead.

Connected through hyperedge HE-1 (induced by source paper "streamable regular transductions"):
  with members:
    - "nested weighted automata"
    - "regular combinators for string transformations"
    - "decision problems for additive regular functions"
    - "streaming tree transducers"
    - "ltl with the freeze quantifier and register automata"
    - "mso definable string transductions and two way finite state transducers"

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)