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: "computing downward closures for stacked counter automata"
  Abstract: The downward closure of a language $L$ of words is the set of all (not necessarily contiguous) subwords of members of $L$. It is well known that the downward closure of any language is regular. Although the downward closure seems to be a promising abstraction, there are only few language classes for which an automaton for the downward closure is known to be computable. #R##N#It is shown here that for stacked counter automata, the downward closure is computable. Stacked counter automata are finite automata with a storage mechanism obtained by \emph{adding blind counters} and \emph{building stacks}. Hence, they generalize pushdown and blind counter automata. #R##N#The class of languages accepted by these automata are precisely those in the hierarchy obtained from the context-free languages by alternating two closure operators: imposing semilinear constraints and taking the algebraic extension. The main tool for computing downward closures is the new concept of Parikh annotations. As a second application of Parikh annotations, it is shown that the hierarchy above is strict at every level.

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"
    - "finite automata for the sub and superword closure of cfls descriptional and computational complexity"
    - "the power of priority channel systems"
    - "complexity bounds for ordinal based termination"
    - "the power of well structured systems"

Connected through hyperedge HE-2 (induced by source paper "ptl separability and closures for wqos on words"):
  with members:
    - "the diagonal problem for higher order recursion schemes is decidable"
    - "unboundedness and downward closures of higher order pushdown automata"
    - "demystifying reachability in vector addition systems"
    - "a characterization for decidable separability by piecewise testable languages"

Connected through hyperedge HE-3 (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"
    - "finite automata for the sub and superword closure of cfls descriptional and computational complexity"
    - "on selective unboundedness of vass"

Connected through hyperedge HE-4 (induced by source paper "the emptiness problem for valence automata over graph monoids"):
  with members:
    - "on the coverability problem for pushdown vector addition systems in one dimension"
    - "silent transitions in automata with storage"
    - "semilinearity and context freeness of languages accepted by valence automata"
    - "approximating petri net reachability along context free traces"

Connected through hyperedge HE-5 (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"
    - "finite automata for the sub and superword closure of cfls descriptional and computational complexity"
    - "alternating towers and piecewise testable separators"
    - "the power of priority channel systems"
    - "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-6 (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"
    - "finite automata for the sub and superword closure of cfls descriptional and computational complexity"
    - "complexity of model checking recursion schemes for fragments of the modal mu calculus"

Connected through hyperedge HE-7 (induced by source paper "an approach to computing downward closures"):
  with members:
    - "on infinite words determined by indexed languages"
    - "regular cost functions part i logic and algebra over words"
    - "silent transitions in automata with storage"
    - "model checking vector addition systems with one zero test"

Connected through hyperedge HE-8 (induced by source paper "a note on decidable separability by piecewise testable languages"):
  with members:
    - "on the state complexity of closures and interiors of regular languages with subwords and superwords"
    - "demystifying reachability in vector addition systems"
    - "an approach to computing downward closures"
    - "the power of well structured systems"
    - "the separation problem for regular languages by piecewise testable languages"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "piecewise testable tree languages"
    - "model checking vector addition systems with one zero test"

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)