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 "the θ 5 graph is a spanner"):
  Abstract: Given a set of points in the plane, we show that the ?-graph with 5 cones is a geometric spanner with spanning ratio at most 50 + 22 5 ? 9.960 . This is the first constant upper bound on the spanning ratio of this graph. The upper bound uses a constructive argument that gives a (possibly self-intersecting) path between any two vertices, of length at most 50 + 22 5 times the Euclidean distance between the vertices. We also give a lower bound on the spanning ratio of 1 2 ( 11 5 - 17 ) ? 3.798 .

Includes members:
  Member "new and improved spanning ratios for yao graphs":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "truly optimal euclidean spanners")
  Member "on the average number of edges in theta graphs":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "maximum matchings and minimum blocking sets in θ 6 graphs")
  Member "on the stretch factor of the theta 4 graph":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "routing in polygonal domains")
  Member "π 2 angle yao graphs are spanners":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "truly optimal euclidean spanners")

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.CG(Computational Geometry)