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: "around dot depth one"
  Abstract: The dot-depth hierarchy is a classification of star-free languages. It is related to the quantifier alternation hierarchy of first-order logic over finite words. We consider fragments of languages with dot-depth 1/2 and dot-depth 1 obtained by prohibiting the specification of prefixes or suffixes. As it turns out, these language classes are in one-to-one correspondence with fragments of existential first-order logic without min- or max-predicate. For all fragments, we obtain effective algebraic characterizations. Moreover, we give new combinatorial proofs for the decidability of the membership problem for dot-depth 1/2 and dot-depth 1.

Connected through hyperedge HE-1 (induced by source paper "adding successor a transfer theorem for separation and covering"):
  with members:
    - "the covering problem"
    - "separating regular languages with two quantifier alternations"
    - "going higher in first order quantifier alternation hierarchies on words"
    - "separating regular languages with first order logic"
    - "quantifier alternation for infinite words"
    - "going higher in the first order quantifier alternation hierarchy on words"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "efficient separability of regular languages by subsequences and suffixes"

Connected through hyperedge HE-2 (induced by source paper "separability by piecewise testable languages is ptime complete"):
  with members:
    - "piecewise testable languages and nondeterministic automata"
    - "going higher in the first order quantifier alternation hierarchy on words"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "efficient separability of regular languages by subsequences and suffixes"
    - "piecewise testable tree languages"

Connected through hyperedge HE-3 (induced by source paper "piecewise testable languages and nondeterministic automata"):
  with members:
    - "on the index of simon s congruence for piecewise testability"
    - "on upper and lower bounds on the length of alternating towers"
    - "alternating towers and piecewise testable separators"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "efficient separability of regular languages by subsequences and suffixes"
    - "piecewise testable tree languages"

Connected through hyperedge HE-4 (induced by source paper "on k piecewise testability preliminary report"):
  with members:
    - "on the index of simon s congruence for piecewise testability"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "succinctness of the complement and intersection of regular expressions"

Connected through hyperedge HE-5 (induced by source paper "quantifier alternation in two variable first order logic with successor is decidable"):
  with members:
    - "lattices of logical fragments over words"
    - "the join levels of the trotter weil hierarchy are decidable"
    - "the fo2 alternation hierarchy is decidable"
    - "structure theorem and strict alternation hierarchy for fo2 on words"

Connected through hyperedge HE-6 (induced by source paper "regular ideal languages and their boolean combinations"):
  with members:
    - "rankers over infinite words"
    - "fragments of first order logic over infinite words"

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)