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: "tractable answer set programming with weight constraints bounded treewidth is not enough"
  Abstract: Cardinality constraints or, more generally, weight constraints are well recognized as an important extension of answer-set programming. Clearly, all common algorithmic tasks related to programs with cardinality or weight constraints - like checking the consistency of a program - are intractable. Many intractable problems in the area of knowledge representation and reasoning have been shown to become linear time tractable if the treewidth of the programs or formulas under consideration is bounded by some constant. The goal of this paper is to apply the notion of treewidth to programs with cardinality or weight constraints and to identify tractable fragments. It will turn out that the straightforward application of treewidth to such class of programs does not suffice to obtain tractability. However, by imposing further restrictions, tractability can be achieved.

Connected through hyperedge HE-1 (induced by source paper "treewidth and counting projected answer sets"):
  with members:
    - "te eth lower bounds for qbfs of bounded treewidth"
    - "exploiting treewidth for projected model counting and its limits"
    - "slightly superexponential parameterized problems"
    - "answer set solving with bounded treewidth revisited"
    - "even faster integer multiplication"

Connected through hyperedge HE-2 (induced by source paper "complexity and approximability of parameterized max csps"):
  with members:
    - "solving maxsat and sat on structured cnf formulas"
    - "guarantees and limits of preprocessing in constraint satisfaction and reasoning"
    - "model counting for formulas of bounded clique width"
    - "a characterization of approximation resistance for even k partite csps"
    - "satisfiability of acyclic and almost acyclic cnf formulas"
    - "majority is stablest discrete and sos"
    - "backdoors to acyclic sat"
    - "not so easy problems for tree decomposable graphs"

Connected through hyperedge HE-3 (induced by source paper "answer set solving with bounded treewidth revisited"):
  with members:
    - "backdoors to tractable answer set programming"

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)