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 spanning and routing ratio of theta four"
  Abstract: We present a routing algorithm for the Theta-4-graph that computes a path between any two vertices s and t having length at most 17 times the Euclidean distance between s and t. To compute this path, at each step, the algorithm only uses knowledge of the location of the current vertex, its (at most four) outgoing edges, the destination vertex, and one additional bit of information in order to determine the next edge to follow. This provides the first known online, local, competitive routing algorithm with constant routing ratio for the Theta-4-graph, as well as improving the best known upper bound on the spanning ratio of these graphs from 237 to 17.

Connected through hyperedge HE-1 (induced by source paper "truly optimal euclidean spanners"):
  with members:
    - "odd yao yao graphs are not spanners"
    - "greedy spanners are optimal in doubling metrics"
    - "minor free graphs have light spanners"
    - "the greedy spanner is existentially optimal"
    - "almost all even yao yao graphs are spanners"
    - "a light metric spanner"
    - "upper bounds on the spanning ratio of constrained theta graphs"
    - "new and improved spanning ratios for yao graphs"

Connected through hyperedge HE-2 (induced by source paper "maximum matchings and minimum blocking sets in θ 6 graphs"):
  with members:
    - "spanning properties of theta theta 6"
    - "the θ 5 graph is a spanner"
    - "higher order triangular distance delaunay graphs graph theoretical properties"
    - "on the average number of edges in theta graphs"
    - "fixed orientation equilateral triangle matching of point sets"
    - "witness gabriel graphs"
    - "witness delaunay graphs"

Connected through hyperedge HE-3 (induced by source paper "expected complexity of routing in theta 6 and half theta 6 graphs"):
  with members:
    - "the θ 5 graph is a spanner"
    - "theta 3 is connected"
    - "towards tight bounds on theta graphs"
    - "optimal local routing on delaunay triangulations defined by empty equilateral triangles"

Connected through hyperedge HE-4 (induced by source paper "spanning properties of theta theta 6"):
  with members:
    - "odd yao yao graphs are not spanners"
    - "almost all even yao yao graphs are spanners"
    - "the θ 5 graph is a spanner"
    - "towards tight bounds on theta graphs"
    - "new and improved spanning ratios for yao graphs"
    - "an infinite class of sparse yao spanners"
    - "π 2 angle yao graphs are spanners"

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)