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: "solving qbf by abstraction"
  Abstract: Many verification and synthesis approaches rely on solving techniques for quantified Boolean formulas (QBF). Consequently, solution witnesses, in the form of Boolean functions, become more and more important as they represent implementations or counterexamples. We present a recursive counterexample guided abstraction and refinement algorithm (CEGAR) for solving and certifying QBFs that exploits structural reasoning on the formula level. The algorithm decomposes the given QBF into one propositional formula for every block of quantifiers that abstracts from assignments of variables not bound by this quantifier block. Further, we show how to derive an efficient certification extraction method on top of the algorithm. We report on experimental evaluation of this algorithm in the solver QuAbS (Quantified Abstraction Solver) which won the most recent QBF competition (QBFEVAL'18). Further, we show the effectiveness of the certification approach using synthesis benchmarks and a case study for synthesizing winning strategies in Petri Games.

Connected through hyperedge HE-1 (induced by source paper "clausal abstraction for dqbf full version"):
  with members:
    - "synthesizing reactive systems from hyperproperties"
    - "bosy an experimentation framework for bounded synthesis"
    - "on expansion and resolution in cegar based qbf solving"
    - "encodings of bounded synthesis"
    - "the 4th reactive synthesis competition syntcomp 2017 benchmarks participants results"
    - "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"

Connected through hyperedge HE-2 (induced by source paper "bosy an experimentation framework for bounded synthesis"):
  with members:
    - "encodings of bounded synthesis"
    - "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"
    - "a high level ltl synthesis format tlsf v1 1"
    - "ltl to b uchi automata translation fast and more deterministic"

Connected through hyperedge HE-3 (induced by source paper "encodings of bounded synthesis"):
  with members:
    - "bounded cycle synthesis"

Connected through hyperedge HE-4 (induced by source paper "the 4th reactive synthesis competition syntcomp 2017 benchmarks participants results"):
  with members:
    - "bosy an experimentation framework for bounded synthesis"
    - "encodings of bounded synthesis"
    - "the first reactive synthesis competition syntcomp 2014"
    - "the reactive synthesis competition syntcomp 2016 and beyond"
    - "bounded cycle synthesis"
    - "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"
    - "a high level ltl synthesis format tlsf v1 1"
    - "specification format for reactive synthesis problems"

Connected through hyperedge HE-5 (induced by source paper "the reactive synthesis competition syntcomp 2016 and beyond"):
  with members:
    - "the first reactive synthesis competition syntcomp 2014"
    - "satisfiability based methods for reactive synthesis from safety specifications"
    - "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"
    - "a high level ltl synthesis format tlsf v1 1"
    - "specification format for reactive synthesis problems"
    - "the second reactive synthesis competition syntcomp 2015"
    - "compositional algorithms for succinct safety games"
    - "assume guarantee synthesis for concurrent reactive programs with partial information"

Connected through hyperedge HE-6 (induced by source paper "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"):
  with members:
    - "the first reactive synthesis competition syntcomp 2014"
    - "the reactive synthesis competition syntcomp 2016 and beyond"
    - "a high level ltl synthesis format tlsf v1 1"
    - "specification format for reactive synthesis problems"
    - "the second reactive synthesis competition syntcomp 2015"
    - "compositional algorithms for succinct safety games"
    - "parameterized synthesis case study amba ahb"
    - "extended aiger format for synthesis"

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)