human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "alternating towers and piecewise testable separators"):
  Abstract: Two languages are separable by a piecewise testable language if and only if there exists no infinite tower between them. An infinite tower is an infinite sequence of strings alternati ng between the two languages such that every string is a subsequence (scattered substring) of all the strings that f ollow. For regular languages represented by nondeterministic finite automata, the existence of an infinite tower is decidab le in polynomial time. In this paper, we investigate the complexity of a particular method to compute a piecewise testable separator. We show that it is closely related to the height of maximal finite towers, and provide the upper and lower bounds with respect to the size of the given nondeterministic automata. Specifically, we show that the u pper bound is polynomial with respect to the number of states with the cardinality of the alphabet in the exponen t. Concerning the lower bound, we show that towers of exponential height with respect to the cardinality of the alphabet exist. Since these towers mostly turn out to be sequences of prefixes, we also provide a comparison with towe rs of prefixes.

Includes members:
  Member "separating regular languages with first order logic":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "regular separability and intersection emptiness are independent problems")
  Member "on the state complexity of closures and interiors of regular languages with subwords and superwords":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "well quasiorders and hierarchy theory")
  Member "on upper and lower bounds on the length of alternating towers":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "on the height of towers of subsequences and prefixes")
  Member "going higher in the first order quantifier alternation hierarchy on words":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "on all things star free")
  Member "separating regular languages by piecewise testable and unambiguous languages":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "partially ordered automata and piecewise testability")
  Member "efficient separability of regular languages by subsequences and suffixes":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "partially ordered automata and piecewise testability")

Question: Please tell me which class the source paper 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)