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: "an overview of nominal typing versus structural typing in object oriented programming with code examples"
  Abstract: NOOP is a mathematical model of nominally-typed OOP that proves the identification of inheritance and subtyping in mainstream nominally-typed OO programming languages and the validity of this identification. This report gives an overview of the main notions in OOP relevant to constructing a mathematical model of OOP such as NOOP. The emphasis in this report is on defining nominality, nominal typing and nominal subtyping of mainstream nominally-typed OO languages, and on contrasting the three notions with their counterparts in structurally-typed OO languages, i.e., with structurality, structural typing and structural subtyping, respectively. An additional appendix demonstrates these notions and other related notions, and the differences between them, using some simple code examples. A detailed, more technical comparison between nominal typing and structural typing in OOP is presented in other publications.

Connected through hyperedge HE-1 (induced by source paper "noop a domain theoretic model of nominally typed oop"):
  with members:
    - "domain theory for modeling oop a summary"

Connected through hyperedge HE-2 (induced by source paper "novel uses of category theory in modeling oop"):
  with members:
    - "towards a java subtyping operad extended version"
    - "why nominal typing matters in oop"
    - "towards an accurate mathematical model of generic nominally typed oop"
    - "towards understanding generics in mainstream oop"
    - "domain theory for modeling oop a summary"

Connected through hyperedge HE-3 (induced by source paper "category theory for modeling oop"):
  with members:
    - "towards a java subtyping operad extended version"
    - "why nominal typing matters in oop"
    - "domain theory for modeling oop a summary"

Connected through hyperedge HE-4 (induced by source paper "a comparison of noop to structural domain theoretic models of oop"):
  with members:
    - "why nominal typing matters in oop"
    - "domain theory for modeling oop a summary"

Connected through hyperedge HE-5 (induced by source paper "a comparison of noop to structural domain theoretic models of object oriented programming"):
  with members:
    - "domain theory for modeling oop a summary"

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)