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 model of cooperative threads"
  Abstract: We develop a model of concurrent imperative programming with threads. We#N#focus on a small imperative language with cooperative threads which execute#N#without interruption until they terminate or explicitly yield control. We#N#define and study a trace-based denotational semantics for this language; this#N#semantics is fully abstract but mathematically elementary. We also give an#N#equational theory for the computational effects that underlie the language,#N#including thread spawning. We then analyze threads in terms of the free algebra#N#monad for this theory.

Connected through hyperedge HE-1 (induced by source paper "behavioural equivalence via modalities for algebraic effects"):
  with members:
    - "quantitative logics for equivalence of effectful programs"
    - "dijkstra monads for all"
    - "dijkstra monads for free"
    - "handling algebraic effects"
    - "abstract effects and proof relevant logical relations"
    - "on csp and the algebraic theory of effects"

Connected through hyperedge HE-2 (induced by source paper "dynamic structural operational semantics"):
  with members:
    - "algebraic meta theory of processes with data"

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)