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 regular ideals"
  Abstract: The state complexity of a regular language is the number of states in a minimal deterministic finite 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 prove that $n^{n-1}$, $n^{n-1}+n-1$, and $n^{n-2}+(n-2)2^{n-2}+1$ are tight upper bounds on the syntactic complexities of right ideals and prefix-closed languages, left ideals and suffix-closed languages, and two-sided ideals and factor-closed languages, respectively. Moreover, we show that the transition semigroups meeting the upper bounds for all three types of ideals are unique, and the numbers of generators (4, 5, and 6, respectively) cannot be reduced.

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"
    - "maximally atomic languages"
    - "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-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"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"

Connected through hyperedge HE-3 (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"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"
    - "quotient complexities of atoms of regular languages"

Connected through hyperedge HE-4 (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"
    - "maximally atomic languages"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"
    - "quotient complexities of atoms of regular languages"
    - "theory of atomata"

Connected through hyperedge HE-5 (induced by source paper "most complex regular ideal 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"
    - "upper bounds on syntactic complexity of left and two sided ideals"
    - "complexity of atoms combinatorially"
    - "symmetric groups and quotient complexity of boolean operations"
    - "quotient complexities of atoms of regular languages"
    - "theory of atomata"

Connected through hyperedge HE-6 (induced by source paper "syntactic complexity of suffix free languages"):
  with members:
    - "complexity of suffix free regular languages"
    - "syntactic complexity of prefix suffix bifix and factor free regular languages"
    - "syntactic complexity of ideal and closed languages"
    - "decision problems for convex languages"
    - "quotient complexity of regular 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)