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 backdoors to tractable constraint languages"
  Abstract: In the context of CSPs, a strong backdoor is a subset of variables such that every complete assignment yields a residual instance guaranteed to have a specified property. If the property allows efficient solving, then a small strong backdoor provides a reasonable decomposition of the original instance into easy instances. An important challenge is the design of algorithms that can find quickly a small strong backdoor if one exists. We present a systematic study of the parameterized complexity of backdoor detection when the target property is a restricted type of constraint language defined by means of a family of polymorphisms. In particular, we show that under the weak assumption that the polymorphisms are idempotent, the problem is unlikely to be FPT when the parameter is either r (the constraint arity) or k (the size of the backdoor) unless P = NP or FPT = W[2]. When the parameter is k+r, however, we are able to identify large classes of languages for which the problem of finding a small backdoor is FPT.

Connected through hyperedge HE-1 (induced by source paper "backdoors into heterogeneous classes of sat and csp"):
  with members:
    - "combining treewidth and backdoors for csp"
    - "discovering archipelagos of tractability for constraint satisfaction and counting"
    - "solving problems on graphs of high rank width"
    - "meta kernelization using well structured modulators"
    - "backdoors to abduction"
    - "strong backdoors to bounded treewidth sat"
    - "the tractability of csp classes defined by forbidden patterns"
    - "backdoors to satisfaction"

Connected through hyperedge HE-2 (induced by source paper "backdoors to tractable valued csp"):
  with members:
    - "the complexity landscape of decompositional parameters for ilp"
    - "differential game logic"
    - "necessary conditions for tractability of valued csps"
    - "discovering archipelagos of tractability for constraint satisfaction and counting"
    - "the complexity of conservative valued csps"
    - "backdoors to normality for disjunctive logic programs"
    - "backdoors to satisfaction"
    - "backdoors to tractable answer set programming"

Connected through hyperedge HE-3 (induced by source paper "combining treewidth and backdoors for csp"):
  with members:
    - "discovering archipelagos of tractability for constraint satisfaction and counting"
    - "designing fpt algorithms for cut problems using randomized contractions"
    - "strong backdoors to bounded treewidth sat"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"
    - "treewidth computation and extremal combinatorics"
    - "hypertree decompositions and tractable queries"

Connected through hyperedge HE-4 (induced by source paper "discovering archipelagos of tractability for constraint satisfaction and counting"):
  with members:
    - "backdoors into heterogeneous classes of sat and csp"
    - "the complexity of conservative valued csps"
    - "an atypical survey of typical case heuristic algorithms"
    - "strong backdoors to bounded treewidth sat"
    - "almost 2 sat is fixed parameter tractable"
    - "the connectivity of boolean satisfiability computational and structural dichotomies"

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.AI(Artificial Intelligence)