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: "mathoid robust scalable fast and accessible math rendering for wikipedia"
  Abstract: Wikipedia is the first address for scientists who want to recap basic mathematical and physical laws and concepts. Today, formulae in those pages are displayed as Portable Network Graphics images. Those images do not integrate well into the text, can not be edited after copying, are inaccessible to screen readers for people with special needs, do not support line breaks for small screens and do not scale for high resolution devices. Mathoid improves this situation and converts formulae specified by Wikipedia editors in a Open image in new window like input format to MathML, with Scalable Vector Graphics images as a fallback solution.

Connected through hyperedge HE-1 (induced by source paper "improving the representation and conversion of mathematical formulae by considering their textual context"):
  with members:
    - "vmext a visualization tool for mathematical expression trees"
    - "interoperability in the opendreamkit project the math in the middle approach"
    - "growing the digital repository of mathematical formulae with generic latex sources"
    - "digital repository of mathematical formulae"
    - "branch cuts in maple 17"
    - "rted a robust algorithm for the tree edit distance"

Connected through hyperedge HE-2 (induced by source paper "vmext a visualization tool for mathematical expression trees"):
  with members:
    - "growing the digital repository of mathematical formulae with generic latex sources"
    - "strategies for parallel markup"
    - "a survey on retrieval of mathematical knowledge"
    - "digital repository of mathematical formulae"

Connected through hyperedge HE-3 (induced by source paper "growing the digital repository of mathematical formulae with generic latex sources"):
  with members:
    - "digital repository of mathematical formulae"
    - "mathematical language processing project"
    - "which one is better presentation based or content based math search"

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.DL(Digital Libraries)