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: "syntactic complexity of prefix suffix bifix and factor free regular languages"
  Abstract: The syntactic complexity of a regular language is the cardinality of its syntactic semigroup. The syntactic complexity of a subclass of the class of regular languages is the maximal syntactic complexity of languages in that class, taken as a function of the state complexity $n$ of these languages. We study the syntactic complexity of prefix-, suffix-, bifix-, and factor-free regular languages. We prove that $n^{n-2}$ is a tight upper bound for prefix-free regular languages. We present properties of the syntactic semigroups of suffix-, bifix-, and factor-free regular languages, conjecture tight upper bounds on their size to be $(n-1)^{n-2}+(n-2)$, $(n-1)^{n-3} + (n-2)^{n-3} + (n-3)2^{n-3}$, and $(n-1)^{n-3} + (n-3)2^{n-3} + 1$, respectively, and exhibit languages with these syntactic complexities.

Connected through hyperedge HE-1 (induced by source paper "syntactic complexity of bifix free languages"):
  with members:
    - "on nonpermutational transformation semigroups with an application to syntactic complexity"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "large aperiodic semigroups"
    - "theory of atomata"
    - "syntactic complexity of ideal and closed languages"
    - "quotient complexity of regular languages"

Connected through hyperedge HE-2 (induced by source paper "complexity of suffix free regular languages"):
  with members:
    - "complexity of proper suffix convex regular languages"
    - "most complex non returning regular languages"
    - "unrestricted state complexity of binary operations on regular languages"
    - "complexity of prefix convex regular languages"
    - "syntactic complexity of bifix free languages"
    - "quotient complexities of atoms in regular ideal languages"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "complexity of atoms combinatorially"

Connected through hyperedge HE-3 (induced by source paper "syntactic complexity of regular ideals"):
  with members:
    - "syntactic complexity of bifix free languages"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "large aperiodic semigroups"
    - "theory of atomata"
    - "syntactic complexity of ideal and closed languages"
    - "quotient complexity of ideal languages"
    - "quotient complexity of closed languages"
    - "decision problems for convex languages"

Connected through hyperedge HE-4 (induced by source paper "syntactic complexity of suffix free languages"):
  with members:
    - "complexity of suffix free regular languages"
    - "syntactic complexity of regular ideals"
    - "syntactic complexity of ideal and closed languages"
    - "decision problems for convex languages"
    - "quotient complexity of regular languages"

Connected through hyperedge HE-5 (induced by source paper "syntactic complexity of r and j trivial regular languages"):
  with members:
    - "syntactic complexity of finite cofinite definite and reverse definite languages"
    - "syntactic complexity of ideal and closed 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)