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 "on the index of simon s congruence for piecewise testability"):
  Abstract: Simon's congruence, denoted by ~ n , relates words having the same subwords of length up to n. We show that, over a k-letter alphabet, the number of words modulo ~ n is in 2 ? ( n k - 1 log ? n ) . We provide upper and lower bounds for Simon's index for piecewise testability.This index depends on the length of considered subwords and the alphabet size.The previously known bounds focused on fixed length of subwords.Our bounds are relevant when alphabet size is fixed and length of subwords vary.They give a growth rate that is exponential and not doubly exponential.

Includes members:
  Member "separating regular languages by piecewise testable and unambiguous languages":
    also connected through other hyperedges:
      - Hyperedge HE-1 (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-2 (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)