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: "the complexity of quantified constraint satisfaction collapsibility sink algebras and the three element case"
  Abstract: The constraint satisfaction probem (CSP) is a well-acknowledged framework in which many combinatorial search problems can be naturally formulated. The CSP may be viewed as the problem of deciding the truth of a logical sentence consisting of a conjunction of constraints, in front of which all variables are existentially quantified. The quantified constraint satisfaction problem (QCSP) is the generalization of the CSP where universal quantification is permitted in addition to existential quantification. The general intractability of these problems has motivated research studying the complexity of these problems under a restricted constraint language, which is a set of relations that can be used to express constraints. #R##N#This paper introduces collapsibility, a technique for deriving positive complexity results on the QCSP. In particular, this technique allows one to show that, for a particular constraint language, the QCSP reduces to the CSP. We show that collapsibility applies to three known tractable cases of the QCSP that were originally studied using disparate proof techniques in different decades: Quantified 2-SAT (Aspvall, Plass, and Tarjan 1979), Quantified Horn-SAT (Karpinski, Kleine B\"{u}ning, and Schmitt 1987), and Quantified Affine-SAT (Creignou, Khanna, and Sudan 2001). This reconciles and reveals common structure among these cases, which are describable by constraint languages over a two-element domain. In addition to unifying these known tractable cases, we study constraint languages over domains of larger size.

Connected through hyperedge HE-1 (induced by source paper "qcsp monsters and the demise of the chen conjecture"):
  with members:
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "the complexity of quantified constraints using the algebraic formulation"
    - "the algebraic dichotomy conjecture for infinite domain constraint satisfaction problems"
    - "quantified constraints and containment problems"
    - "the complexity of general valued csps"
    - "from complexity to algebra and back digraph classes collapsibility and the pgp"
    - "on the complexity of the model checking problem"

Connected through hyperedge HE-2 (induced by source paper "the proof of csp dichotomy conjecture"):
  with members:
    - "algebraic approach to promise constraint satisfaction"
    - "a modifiction of the csp algorithm for infinite languages"
    - "a dichotomy theorem for nonuniform csps"
    - "the complexity of quantified constraints using the algebraic formulation"
    - "weaker consistency notions for all the csps of bounded width"
    - "the algebraic dichotomy conjecture for infinite domain constraint satisfaction problems"
    - "an algebraic hardness criterion for surjective constraint satisfaction"
    - "complexity classification in infinite domain constraint satisfaction"

Connected through hyperedge HE-3 (induced by source paper "from complexity to algebra and back digraph classes collapsibility and the pgp"):
  with members:
    - "quantified constraints and containment problems"
    - "on the complexity of the model checking problem"
    - "meditations on quantified constraint satisfaction"
    - "containment equivalence and coreness from csp to qcsp and beyond"
    - "qcsp on partially reflexive forests"
    - "the complexity of positive first order logic without equality"

Connected through hyperedge HE-4 (induced by source paper "quantified constraints and containment problems"):
  with members:
    - "containment equivalence and coreness from csp to qcsp and beyond"
    - "semantical characterizations and complexity of equivalences in answer set programming"

Connected through hyperedge HE-5 (induced by source paper "qcsp on partially reflexive cycles the wavy line of tractability"):
  with members:
    - "quantified constraints and containment problems"
    - "meditations on quantified constraint satisfaction"
    - "containment equivalence and coreness from csp to qcsp and beyond"
    - "qcsp on partially reflexive forests"

Connected through hyperedge HE-6 (induced by source paper "an algebraic preservation theorem for aleph zero categorical quantified constraint satisfaction"):
  with members:
    - "quantified constraints and containment problems"
    - "on the scope of the universal algebraic approach to constraint satisfaction"
    - "complexity of existential positive first order logic"
    - "the complexity of positive first order logic without equality"

Connected through hyperedge HE-7 (induced by source paper "meditations on quantified constraint satisfaction"):
  with members:
    - "generic expression hardness results for primitive positive formula comparison"
    - "existentially restricted quantified constraint satisfaction"

Connected through hyperedge HE-8 (induced by source paper "low level dichotomy for quantified constraint satisfaction problems"):
  with members:
    - "a formal foundation for xrml"
    - "a characterisation of first order constraint satisfaction problems"
    - "interactive small step algorithms ii abstract state machines and the characterization theorem"

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)