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: "using bounded model checking to focus fixpoint iterations"
  Abstract: Two classical sources of imprecision in static analysis by abstract interpretation are widening and merge operations. Merge operations can be done away by distinguishing paths, as in trace partitioning, at the expense of enumerating an exponential number of paths. In this article, we describe how to avoid such systematic exploration by focusing on a single path at a time, designated by SMT-solving. Our method combines well with acceleration techniques, thus doing away with widenings as well in some cases. We illustrate it over the well-known domain of convex polyhedra.

Connected through hyperedge HE-1 (induced by source paper "combining forward and backward abstract interpretation of horn clauses"):
  with members:
    - "program analysis with local policy iteration"
    - "smt based model checking for recursive programs"
    - "automatic abstraction in smt based unbounded software model checking"
    - "pagai a path sensitive static analyzer"
    - "the parma polyhedra library toward a complete set of numerical abstractions for the analysis and verification of hardware and software systems"

Connected through hyperedge HE-2 (induced by source paper "program analysis with local policy iteration"):
  with members:
    - "invariant generation through strategy iteration in succinctly represented control flow graphs"
    - "pagai a path sensitive static analyzer"
    - "automatic modular abstractions for template numerical constraints"
    - "cpachecker a tool for configurable software verification"
    - "the octagon abstract domain"

Connected through hyperedge HE-3 (induced by source paper "formula slicing inductive invariants from preconditions"):
  with members:
    - "program analysis with local policy iteration"
    - "automatic abstraction in smt based unbounded software model checking"
    - "pagai a path sensitive static analyzer"
    - "software model checking via large block encoding"
    - "cpachecker a tool for configurable software verification"

Connected through hyperedge HE-4 (induced by source paper "efficiently intertwining widening and narrowing"):
  with members:
    - "pagai a path sensitive static analyzer"
    - "succinct representations for abstract interpretation"
    - "stratified static analysis based on variable dependencies"
    - "a static analyzer for large safety critical software"

Connected through hyperedge HE-5 (induced by source paper "invariant generation through strategy iteration in succinctly represented control flow graphs"):
  with members:
    - "succinct representations for abstract interpretation"
    - "optimization in smt with la q cost functions"
    - "numerical invariants through convex relaxation and max strategy iteration"
    - "improving strategies via smt solving"
    - "automatic modular abstractions for template numerical constraints"
    - "the octagon abstract domain"
    - "symbolic methods to enhance the precision of numerical abstract domains"
    - "a static analyzer for large safety critical software"

Connected through hyperedge HE-6 (induced by source paper "pagai a path sensitive static analyzer"):
  with members:
    - "succinct representations for abstract interpretation"
    - "symbolic methods to enhance the precision of numerical abstract domains"
    - "the parma polyhedra library toward a complete set of numerical abstractions for the analysis and verification of hardware and software systems"
    - "a static analyzer for large safety critical software"

Connected through hyperedge HE-7 (induced by source paper "succinct representations for abstract interpretation"):
  with members:
    - "improving strategies via smt solving"
    - "the octagon abstract domain"
    - "the parma polyhedra library toward a complete set of numerical abstractions for the analysis and verification of hardware and software systems"
    - "a static analyzer for large safety critical software"

Connected through hyperedge HE-8 (induced by source paper "invariant stream generators using automatic abstract transformers based on a decidable logic"):
  with members:
    - "pkind a parallel k induction based model checker"
    - "improving strategies via smt solving"
    - "automatic modular abstractions for linear constraints"

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)