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: "on the stretch factor of convex delaunay graphs"
  Abstract: Let C be a compact and convex set in the plane that contains the origin in its interior, and let S be a finite set of points in the plane. The Delaunay graph DG_C(S) of S is defined to be the dual of the Voronoi diagram of S with respect to the convex distance function defined by C. We prove that DG_C(S) is a t-spanner for S, for some constant t that depends only on the shape of the set C. Thus, for any two points p and q in S, the graph DG_C(S) contains a path between p and q whose Euclidean length is at most t times the Euclidean distance between p and q.

Connected through hyperedge HE-1 (induced by source paper "angle monotone graphs construction and local routing"):
  with members:
    - "angle monotone paths in non obtuse triangulations"
    - "gabriel triangulations and angle monotone graphs local routing and recognition"
    - "optimal local routing on delaunay triangulations defined by empty equilateral triangles"
    - "increasing chord graphs on point sets"

Connected through hyperedge HE-2 (induced by source paper "the stretch factor of hexagon delaunay triangulations"):
  with members:
    - "the stretch factor of the delaunay triangulation is less than 1 998"

Connected through hyperedge HE-3 (induced by source paper "matchings in geometric graphs"):
  with members:
    - "packing plane spanning trees and paths in complete geometric graphs"
    - "flip distance to a non crossing perfect matching"
    - "balanced partitions of 3 colored geometric sets in the plane"
    - "packing plane perfect matchings into a point set"
    - "10 gabriel graphs are hamiltonian"
    - "higher order triangular distance delaunay graphs graph theoretical properties"
    - "approximating the bottleneck plane perfect matching of a point set"
    - "fixed orientation equilateral triangle matching of point sets"

Connected through hyperedge HE-4 (induced by source paper "almost all even yao yao graphs are spanners"):
  with members:
    - "new and improved spanning ratios for yao graphs"
    - "an infinite class of sparse yao spanners"
    - "π 2 angle yao graphs are spanners"
    - "a simple yao yao based spanner of bounded degree"

Connected through hyperedge HE-5 (induced by source paper "degree four plane spanners simpler and better"):
  with members:
    - "the stretch factor of the delaunay triangulation is less than 1 998"
    - "on geometric spanners of euclidean and unit disk graphs"

Connected through hyperedge HE-6 (induced by source paper "constrained generalized delaunay graphs are plane spanners"):
  with members:
    - "on plane constrained bounded degree spanners"
    - "the stretch factor of the delaunay triangulation is less than 1 998"

Connected through hyperedge HE-7 (induced by source paper "strong matching of points with geometric shapes"):
  with members:
    - "matching in gabriel graphs"
    - "higher order triangular distance delaunay graphs graph theoretical properties"
    - "fixed orientation equilateral triangle matching of point sets"

Connected through hyperedge HE-8 (induced by source paper "higher order triangular distance delaunay graphs graph theoretical properties"):
  with members:
    - "10 gabriel graphs are hamiltonian"
    - "fixed orientation equilateral triangle matching of point sets"
    - "witness gabriel graphs"

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.CG(Computational Geometry)