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: "on expansion and resolution in cegar based qbf solving"
  Abstract: A quantified Boolean formula (QBF) is a propositional formula extended with universal and existential quantification over propositions. There are two methodologies in CEGAR based QBF solving techniques, one that is based on a refinement loop that builds partial expansions and a more recent one that is based on the communication of satisfied clauses. Despite their algorithmic similarity, their performance characteristics in experimental evaluations are very different and in many cases orthogonal. We compare those CEGAR approaches using proof theory developed around QBF solving and present a unified calculus that combines the strength of both approaches. Lastly, we implement the new calculus and confirm experimentally that the theoretical improvements lead to improved performance.

Connected through hyperedge HE-1 (induced by source paper "qratpre effective qbf preprocessing via strong redundancy properties"):
  with members:
    - "expansion based qbf solving without recursion"
    - "evaluating qbf solvers quantifier alternations matter"
    - "textsf qrat generalizing qrat by a more powerful qbf redundancy property"
    - "depqbf 6 0 a search based qbf solver beyond traditional qcdcl"
    - "the qbf gallery"
    - "clause term resolution and learning in the evaluation of quantified boolean formulas"

Connected through hyperedge HE-2 (induced by source paper "understanding and extending incremental determinization for 2qbf"):
  with members:
    - "encodings of bounded synthesis"
    - "qbf solving by counterexample guided expansion"
    - "a theory of formal synthesis via inductive learning"

Connected through hyperedge HE-3 (induced by source paper "solving qbf by abstraction"):
  with members:
    - "bosy an experimentation framework for bounded synthesis"
    - "encodings of bounded synthesis"
    - "the 4th reactive synthesis competition syntcomp 2017 benchmarks participants results"
    - "symbolic vs bounded synthesis for petri games"
    - "the first reactive synthesis competition syntcomp 2014"
    - "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"
    - "detecting unrealizability of distributed fault tolerant systems"
    - "petri games synthesis of distributed systems with causal memory"

Connected through hyperedge HE-4 (induced by source paper "expansion based qbf solving without recursion"):
  with members:
    - "evaluating qbf solvers quantifier alternations matter"
    - "encodings of bounded synthesis"
    - "depqbf 6 0 a search based qbf solver beyond traditional qcdcl"
    - "structural synthesis for gxw specifications"
    - "detecting unrealizability of distributed fault tolerant systems"
    - "conformant planning as a case study of incremental qbf solving"

Connected through hyperedge HE-5 (induced by source paper "evaluating qbf solvers quantifier alternations matter"):
  with members:
    - "size cost and capacity a semantic technique for hard random qbfs"
    - "depqbf 6 0 a search based qbf solver beyond traditional qcdcl"
    - "the qbf gallery"
    - "proof complexity modulo the polynomial hierarchy understanding alternation as a source of hardness"
    - "meditations on quantified constraint satisfaction"
    - "clause term resolution and learning in the evaluation of quantified boolean formulas"

Connected through hyperedge HE-6 (induced by source paper "clausal abstraction for dqbf full version"):
  with members:
    - "synthesizing reactive systems from hyperproperties"
    - "bosy an experimentation framework for bounded synthesis"
    - "encodings of bounded synthesis"
    - "solving qbf by abstraction"
    - "the 4th reactive synthesis competition syntcomp 2017 benchmarks participants results"
    - "the 3rd reactive synthesis competition syntcomp 2016 benchmarks participants results"

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)