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: "finite automata for the sub and superword closure of cfls descriptional and computational complexity"
  Abstract: We answer two open questions by (Gruber, Holzer, Kutrib, 2009) on the state-complexity of representing sub- or superword closures of context-free grammars (CFGs): (1) We prove a (tight) upper bound of $2^{\mathcal{O}(n)}$ on the size of nondeterministic finite automata (NFAs) representing the subword closure of a CFG of size $n$. (2) We present a family of CFGs for which the minimal deterministic finite automata representing their subword closure matches the upper-bound of $2^{2^{\mathcal{O}(n)}}$ following from (1). Furthermore, we prove that the inequivalence problem for NFAs representing sub- or superword-closed languages is only NP-complete as opposed to PSPACE-complete for general NFAs. Finally, we extend our results into an approximation method to attack inequivalence problems for CFGs.

Connected through hyperedge HE-1 (induced by source paper "the ideal approach to computing closed subsets in well quasi orderings"):
  with members:
    - "mixed powerdomains for probability and nondeterminism"
    - "well behaved transition systems"
    - "complexity hierarchies beyond elementary"
    - "demystifying reachability in vector addition systems"
    - "the power of priority channel systems"
    - "complexity bounds for ordinal based termination"
    - "computing downward closures for stacked counter automata"
    - "the power of well structured systems"

Connected through hyperedge HE-2 (induced by source paper "on the upward downward closures of petri nets"):
  with members:
    - "complexity of regular abstractions of one counter languages"
    - "unboundedness and downward closures of higher order pushdown automata"
    - "an approach to computing downward closures"
    - "a characterization for decidable separability by piecewise testable languages"
    - "computing downward closures for stacked counter automata"
    - "on selective unboundedness of vass"

Connected through hyperedge HE-3 (induced by source paper "on the state complexity of closures and interiors of regular languages with subwords and superwords"):
  with members:
    - "decidability in the logic of subsequences and supersequences"
    - "refinement and difference for probabilistic automata"
    - "alternating towers and piecewise testable separators"
    - "the power of priority channel systems"
    - "computing downward closures for stacked counter automata"
    - "quotient complexity of ideal languages"
    - "decision problems for convex languages"
    - "the computational complexity of universality problems for prefixes suffixes factors and subwords of regular languages"

Connected through hyperedge HE-4 (induced by source paper "the diagonal problem for higher order recursion schemes is decidable"):
  with members:
    - "on word and frontier languages of unsafe higher order grammars"
    - "unboundedness and downward closures of higher order pushdown automata"
    - "ordered tree pushdown systems"
    - "an approach to computing downward closures"
    - "using models to model check recursive schemes"
    - "a characterization for decidable separability by piecewise testable languages"
    - "computing downward closures for stacked counter automata"
    - "complexity of model checking recursion schemes for fragments of the modal mu calculus"

Connected through hyperedge HE-5 (induced by source paper "the height of piecewise testable languages and the complexity of the logic of subwords"):
  with members:
    - "piecewise testable languages and nondeterministic automata"
    - "on the state complexity of closures and interiors of regular languages with subwords and superwords"
    - "decidability in the logic of subsequences and supersequences"
    - "on the index of simon s congruence for piecewise testability"
    - "an approach to computing downward closures"
    - "the height of piecewise testable languages with applications in logical complexity"
    - "recompression a simple and powerful technique for word equations"
    - "piecewise testable tree 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)