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: "modular analysis via specifications as values"
  Abstract: Modular static analysis requires treating some portion of t he program opaquely. To enable such analysis, we introduce a notion of abstract reduction semantics. Opaque components are approximated by their specifications, which in turn are treated as a bstract values during reduction. We demonstrate the technique by applying it to two kinds of specifications for higher-order languages : types and first-class contracts, showing that each soundly approx imates opaque components. Finally, we derive modular static analyzers from these semantics, soundly predicting evaluation, contract violations, and blame assignment.

Connected through hyperedge HE-1 (induced by source paper "semantic solutions to program analysis problems"):
  with members:
    - "resolving and exploiting the k cfa paradox"
    - "abstracting abstract machines"

Connected through hyperedge HE-2 (induced by source paper "abstracting abstract machines a systematic approach to higher order program analysis"):
  with members:
    - "deciding k cfa is complete for exptime"

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)