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: "a universal grammar based code for lossless compression of binary trees"
  Abstract: We consider the problem of lossless compression of binary trees, with the aim of reducing the number of code bits needed to store or transmit such trees. A lossless grammar-based code is presented which encodes each binary tree into a binary codeword in two steps. In the first step, the tree is transformed into a context-free grammar from which the tree can be reconstructed. In the second step, the context-free grammar is encoded into a binary codeword. The decoder of the grammar-based code decodes the original tree from its codeword by reversing the two encoding steps. It is shown that the resulting grammar-based binary tree compression code is a universal code on a family of probabilistic binary tree source models satisfying certain weak restrictions.

Connected through hyperedge HE-1 (induced by source paper "entropy bounds for grammar based tree compressors"):
  with members:
    - "grammar based compression of unranked trees"
    - "using statistical encoding to achieve tree succinctness never seen before"
    - "entropy bounds for grammar compression"
    - "a universal tree balancing theorem"
    - "universal tree source coding using grammar based compression"
    - "large alphabets and incompressibility"
    - "identifying hierarchical structure in sequences a linear time algorithm"

Connected through hyperedge HE-2 (induced by source paper "average case analysis of leaf centric binary tree sources"):
  with members:
    - "universal tree source coding using grammar based compression"

Connected through hyperedge HE-3 (induced by source paper "hypotheses testing on infinite random graphs"):
  with members:
    - "independence clustering without a matrix"
    - "universal codes as a basis for time series testing"
    - "application of kolmogorov complexity and universal codes to identity testing and nonparametric testing of serial independence for time series"

Connected through hyperedge HE-4 (induced by source paper "universal tree source coding using grammar based compression"):
  with members:
    - "tree compression with top trees revisited"

Connected through hyperedge HE-5 (induced by source paper "constructing small tree grammars and small circuits for formulas"):
  with members:
    - "traversing grammar compressed trees with constant delay"
    - "tree compression with top trees revisited"
    - "a really simple approximation of smallest grammar"
    - "tree compression with top trees"
    - "approximation of grammar based compression via recompression"
    - "approximation of smallest linear tree grammar"
    - "grammar based compression in a streaming model"

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.IT(Information Theory)