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 protocol for instruction stream processing"
  Abstract: The behaviour produced by an instruction sequence under execution is a behaviour to be controlled by some execution environment: each step performed actuates the processing of an instruction by the execution environment and a reply returned at completion of the processing determines how the behaviour proceeds. In this paper, we are concerned with the case where the processing takes place remotely. We describe a protocol to deal with the case where the behaviour produced by an instruction sequence under execution leads to the generation of a stream of instructions to be processed and a remote execution unit handles the processing of that stream of instructions.

Connected through hyperedge HE-1 (induced by source paper "from functions to object orientation by abstraction"):
  with members:
    - "a process calculus with finitary comprehended terms"
    - "instruction sequence processing operators"
    - "on the expressiveness of single pass instruction sequences"
    - "indirect jumps improve instruction sequence performance"
    - "concurrent models for object execution"
    - "communicating concurrent functions"
    - "concurrent models for function execution"
    - "thread algebra for poly threading"

Connected through hyperedge HE-2 (induced by source paper "on the behaviours produced by instruction sequences under execution"):
  with members:
    - "instruction sequence processing operators"
    - "on the expressiveness of single pass instruction sequences"
    - "indirect jumps improve instruction sequence performance"
    - "on the operating unit size of load store architectures"
    - "transmission protocols for instruction streams"
    - "an instruction sequence semigroup with involutive anti automorphisms"
    - "program algebra with a jump shift instruction"
    - "instruction sequences and non uniform complexity theory"

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)