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 "estimation and verification of partially observed discrete event systems"):
  Abstract: This article considers state estimation and veri cation problems for an important class of man-made cyber-physical systems called Discrete-Event Systems (DES).

Includes members:
  Member "opacity of nondeterministic transition systems a bi simulation relation approach":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on approximate opacity of cyber physical systems")
  Member "deciding detectability for labeled petri nets":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "verification of detectability in petri nets using verifier nets")
  Member "complexity of detectability opacity and a diagnosability for modular discrete event systems":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "partially ordered automata and piecewise testability")
  Member "complexity of deciding detectability in discrete event systems":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "partially ordered automata and piecewise testability")
  Member "probabilistic opacity for markov decision processes":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "compositional and abstraction based approach for synthesis of edit functions for opacity enforcement")

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.SY(Systems and Control)