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: "java subtyping as an infinite self similar partial graph product"
  Abstract: Due to supporting variance annotations, such as wildcard types, the subtyping relation in Java and other generic nominally-typed OO programming languages is both interesting and intricate. In these languages, the subtyping relation between ground object types (ones with no type variables) is the basis for defining the full OO subtyping relation (i.e., that includes type variables). #R##N#In this paper we present how the subtyping relation between ground Java types can be precisely constructed using a binary operation on directed graphs. The binary operation we use, called a partial Cartesian graph product, is similar in its essence to standard graph products and group products. Its definition is based in particular on that of the standard Cartesian graph product. #R##N#We believe the use of this graph operation in constructing the ground generic Java subtyping relation reveals some of the not-immediately-obvious structure of the subtyping relation in generic nominally-typed OO programming languages. Accordingly, we believe that describing precisely how this graph operation is used to construct the subtyping relation of these languages, as we do in this paper, may significantly improve our understanding of wildcard types and variance annotations in those languages.

Connected through hyperedge HE-1 (induced by source paper "java generics an order theoretic approach abridged outline"):
  with members:
    - "induction coinduction and fixed points intuitions and tutorial"
    - "java generics an order theoretic approach detailed outline"
    - "induction coinduction and fixed points in pl type theory"
    - "towards taming java wildcards and extending java with interval types"
    - "doubly f bounded generics"
    - "towards understanding generics"

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.PL(Programming Languages)