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 representation theorem for second order functionals"
  Abstract: Representation theorems relate seemingly complex objects to concrete, more tractable ones. #R##N#In this paper, we take advantage of the abstraction power of category theory and provide a general representation theorem for a wide class of second-order functionals which are polymorphic over a class of functors. Types polymorphic over a class of functors are easily representable in languages such as Haskell, but are difficult to analyse and reason about. The concrete representation provided by the theorem is easier to analyse, but it might not be as convenient to implement. Therefore, depending on the task at hand, the change of representation may prove valuable in one direction or the other. #R##N#We showcase the usefulness of the representation theorem with a range of examples. Concretely, we show how the representation theorem can be used to show that traversable functors are finitary containers, how parameterised coalgebras relate to very well-behaved lenses, and how algebraic effects might be implemented in a functional language.

Connected through hyperedge HE-1 (induced by source paper "profunctor optics and traversals"):
  with members:
    - "understanding profunctor optics a representation theorem"
    - "profunctor optics modular data accessors"
    - "reflections on monadic lenses"
    - "compositional game theory"
    - "notions of computation as monoids"
    - "an investigation of the laws of traversals"

Connected through hyperedge HE-2 (induced by source paper "profunctor optics a categorical update"):
  with members:
    - "profunctor optics and traversals"
    - "understanding profunctor optics a representation theorem"
    - "lenses and learners"
    - "profunctor optics modular data accessors"
    - "compositional game theory"

Connected through hyperedge HE-3 (induced by source paper "understanding profunctor optics a representation theorem"):
  with members:
    - "profunctor optics modular data accessors"
    - "reflections on monadic lenses"

Connected through hyperedge HE-4 (induced by source paper "generic deriving of generic traversals"):
  with members:
    - "profunctor optics modular data accessors"
    - "functor is to lens as applicative is to biplate introducing multiplate"

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)