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 ideal and closed languages"
  Abstract: The state complexity of a regular language is the number of states in the minimal deterministic automaton accepting the language. The syntactic complexity of a regular language is the cardinality of its syntactic semigroup. The syntactic complexity of a subclass of regular languages is the worst-case syntactic complexity taken as a function of the state complexity $n$ of languages in that class. We study the syntactic complexity of the class of regular ideal languages and their complements, the closed languages. We prove that $n^{n-1}$ is a tight upper bound on the complexity of right ideals and prefix-closed languages, and that there exist left ideals and suffix-closed languages of syntactic complexity $n^{n-1}+n-1$, and two-sided ideals and factor-closed languages of syntactic complexity $n^{n-2}+(n-2)2^{n-2}+1$.

Connected through hyperedge HE-1 (induced by source paper "towards a theory of complexity of regular languages"):
  with members:
    - "most complex non returning regular languages"
    - "unrestricted state complexity of binary operations on regular languages"
    - "unrestricted state complexity of binary operations on regular and ideal languages"
    - "most complex regular ideal languages"
    - "syntactic complexity of regular ideals"
    - "maximally atomic languages"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "complexity of atoms combinatorially"

Connected through hyperedge HE-2 (induced by source paper "most complex non returning regular languages"):
  with members:
    - "a new technique for reachability of states in concatenation automata"
    - "unrestricted state complexity of binary operations on regular languages"
    - "on the state complexity of the shuffle of regular languages"
    - "unrestricted state complexity of binary operations on regular and ideal languages"
    - "quotient complexities of atoms in regular ideal languages"
    - "complexity of suffix free regular languages"
    - "syntactic complexity of regular ideals"
    - "complexity of atoms combinatorially"

Connected through hyperedge HE-3 (induced by source paper "complexity of regular bifix free languages"):
  with members:
    - "most complex non returning regular languages"
    - "most complex regular ideals"
    - "complexity of atoms combinatorially"
    - "theory of atomata"
    - "decision problems for convex languages"
    - "quotient complexity of regular languages"

Connected through hyperedge HE-4 (induced by source paper "complexity of left ideal suffix closed and suffix free regular languages"):
  with members:
    - "unrestricted state complexity of binary operations on regular languages"
    - "unrestricted state complexity of binary operations on regular and ideal languages"
    - "quotient complexities of atoms in regular ideal languages"
    - "most complex regular ideal languages"
    - "syntactic complexity of regular ideals"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"

Connected through hyperedge HE-5 (induced by source paper "complexity of prefix convex regular languages"):
  with members:
    - "unrestricted state complexity of binary operations on regular languages"
    - "quotient complexities of atoms in regular ideal languages"
    - "most complex regular ideal languages"
    - "syntactic complexity of regular ideals"
    - "maximally atomic languages"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"
    - "quotient complexities of atoms of regular languages"

Connected through hyperedge HE-6 (induced by source paper "unrestricted state complexity of binary operations on regular and ideal languages"):
  with members:
    - "unrestricted state complexity of binary operations on regular languages"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"
    - "theory of atomata"
    - "transition complexity of incomplete dfas"
    - "quotient complexity of ideal languages"
    - "quotient complexity of regular languages"

Connected through hyperedge HE-7 (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"
    - "syntactic complexity of prefix suffix bifix and factor free regular languages"
    - "theory of atomata"
    - "quotient complexity of regular languages"

Connected through hyperedge HE-8 (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"

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)