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: "varieties of languages in a category"
  Abstract: Eilenberg's variety theorem, a centerpiece of algebraic automata theory, establishes a bijective correspondence between varieties of languages and pseudovarieties of monoids. In the present paper this result is generalized to an abstract pair of algebraic categories: we introduce varieties of languages in a category C, and prove that they correspond to pseudovarieties of monoids in a closed monoidal category D, provided that C and D are dual on the level of finite objects. By suitable choices of these categories our result uniformly covers Eilenberg's theorem and three variants due to Pin, Polak and Reutenauer, respectively, and yields new Eilenberg-type correspondences.

Connected through hyperedge HE-1 (induced by source paper "syntactic structures of regular languages"):
  with members:
    - "one eilenberg theorem to rule them all"
    - "eilenberg theorems for free"
    - "recognisable languages over monads"
    - "profinite monads profinite equations and reiterman s theorem"
    - "generalized eilenberg theorem i local varieties of languages"
    - "on varieties of automata enriched with an algebraic structure extended abstract"
    - "proceedings 14th international conference on automata and formal languages"

Connected through hyperedge HE-2 (induced by source paper "one eilenberg theorem to rule them all"):
  with members:
    - "syntactic monoids in a category"
    - "recognisable languages over monads"
    - "profinite monads profinite equations and reiterman s theorem"
    - "a fibrational approach to automata theory"
    - "generalized eilenberg theorem i local varieties of languages"

Connected through hyperedge HE-3 (induced by source paper "the sch utzenberger product for syntactic spaces"):
  with members:
    - "using duality in circuit complexity"

Connected through hyperedge HE-4 (induced by source paper "profinite monads profinite equations and reiterman s theorem"):
  with members:
    - "syntactic monoids in a category"
    - "recognisable languages over monads"
    - "a fibrational approach to automata theory"
    - "generalized eilenberg theorem i local varieties of languages"

Connected through hyperedge HE-5 (induced by source paper "a fibrational approach to automata theory"):
  with members:
    - "generalized eilenberg theorem i local varieties of 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)