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: "pkind a parallel k induction based model checker"
  Abstract: PKIND is a novel parallel k-induction-based model checker of invariant properties for finite- or infinite-state Lustre programs. Its architecture, which is strictly message-based, is designed to minimize synchronization delays and easily accommodate the incorporation of incremental invariant generators to enhance basic k-induction. We describe PKIND’s functionality and main features, and present experimental evidence that PKIND significantly speeds up the verification of safety properties and, due to incremental invariant generation, also considerably increases the number of provable ones.

Connected through hyperedge HE-1 (induced by source paper "the jkind model checker"):
  with members:
    - "efficient generation of inductive validity cores for safety properties"
    - "combining k induction with continuously refined invariants"
    - "requirements analysis of a quad redundant flight control system"
    - "ic3 modulo theories via implicit predicate abstraction"

Connected through hyperedge HE-2 (induced by source paper "hierarchical state machines as modular horn clauses"):
  with members:
    - "automatic abstraction in smt based unbounded software model checking"

Connected through hyperedge HE-3 (induced by source paper "model counting modulo theories"):
  with members:
    - "on bounding problems of quantitative information flow"
    - "tarmo a framework for parallelized bounded model checking"
    - "the good old davis putnam procedure helps counting models"

Connected through hyperedge HE-4 (induced by source paper "combining k induction with continuously refined invariants"):
  with members:
    - "smt based bounded model checking for embedded ansi c software"
    - "cpachecker a tool for configurable software verification"

Connected through hyperedge HE-5 (induced by source paper "model checking c programs with loops via k induction and invariants"):
  with members:
    - "smt based bounded model checking for embedded ansi c software"

Connected through hyperedge HE-6 (induced by source paper "using dynamic analysis to generate disjunctive invariants"):
  with members:
    - "automated fixing of programs with contracts"
    - "a static analyzer for large safety critical software"

Connected through hyperedge HE-7 (induced by source paper "ic3 modulo theories via implicit predicate abstraction"):
  with members:
    - "smt based induction methods for timed systems"

Connected through hyperedge HE-8 (induced by source paper "generating property directed potential invariants by backward analysis"):
  with members:
    - "a quantifier elimination algorithm for linear real arithmetic"
    - "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"

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.LO(Logic in Computer Science)