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: "hybrid tractability of valued constraint problems"
  Abstract: The constraint satisfaction problem (CSP) is a central generic problem in computer science and artificial intelligence: it provides a common framework for many theoretical problems as well as for many real-life applications. Valued constraint problems are a generalisation of the CSP which allow the user to model optimisation problems. Considerable effort has been made in identifying properties which ensure tractability in such problems. In this work, we initiate the study of hybrid tractability of valued constraint problems; that is, properties which guarantee tractability of the given valued constraint problem, but which do not depend only on the underlying structure of the instance (such as being tree-structured) or only on the types of valued constraints in the instance (such as submodularity). We present several novel hybrid classes of valued constraint problems in which all unary constraints are allowed, which include a machine scheduling problem, constraint problems of arbitrary arities with no overlapping nogoods, and the SoftAllDiff constraint with arbitrary unary valued constraints. An important tool in our investigation will be the notion of forbidden substructures.

Connected through hyperedge HE-1 (induced by source paper "binary constraint satisfaction problems defined by excluded topological minors"):
  with members:
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "the power of arc consistency for csps defined by partially ordered forbidden patterns"
    - "variable and value elimination in binary constraint satisfaction via forbidden patterns"
    - "the tractability of csp classes defined by forbidden patterns"
    - "finding topological subgraphs is fixed parameter tractable"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"

Connected through hyperedge HE-2 (induced by source paper "a tractable class of binary vcsps via m convex intersection"):
  with members:
    - "discrete convexity in joint winner property"
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "the complexity of general valued csps"
    - "tractable triangles and cross free convexity in discrete optimisation"
    - "tractable optimization problems through hypergraph based structural restrictions"

Connected through hyperedge HE-3 (induced by source paper "discrete convexity in joint winner property"):
  with members:
    - "tractable triangles and cross free convexity in discrete optimisation"

Connected through hyperedge HE-4 (induced by source paper "on singleton arc consistency for csps defined by monotone patterns"):
  with members:
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "weaker consistency notions for all the csps of bounded width"
    - "the power of arc consistency for csps defined by partially ordered forbidden patterns"
    - "variable and value elimination in binary constraint satisfaction via forbidden patterns"
    - "the tractability of csp classes defined by forbidden patterns"
    - "arc consistency and friends"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"

Connected through hyperedge HE-5 (induced by source paper "the complexity of finite valued csps"):
  with members:
    - "an algebraic theory of complexity for discrete optimization"
    - "the complexity of conservative valued csps"
    - "the power of linear programming for general valued csps"
    - "computational complexity of the minimum cost homomorphism problem on three element domains"
    - "tractable triangles and cross free convexity in discrete optimisation"
    - "the power of linear programming for valued csps"
    - "an effective fusion technique of cloud computing and networking series"
    - "tractable optimization problems through hypergraph based structural restrictions"

Connected through hyperedge HE-6 (induced by source paper "even delta matroids and the complexity of planar boolean csps"):
  with members:
    - "a dichotomy theorem for nonuniform csps"
    - "the proof of csp dichotomy conjecture"
    - "the complexity of finite valued csps"
    - "algebraic properties of valued constraint satisfaction problem"
    - "the complexity of general valued csps"
    - "effectiveness of structural restrictions for hybrid csps"
    - "the complexity of conservative valued csps"
    - "approximate constraint satisfaction requires large lp relaxations"

Connected through hyperedge HE-7 (induced by source paper "greedy strategies and larger islands of tractability for conjunctive queries and constraint satisfaction problems"):
  with members:
    - "constraint solving via fractional edge covers"
    - "flexible caching in trie joins"
    - "gym a multiround join algorithm in mapreduce"
    - "a quasi polynomial time partition oracle for graphs with an excluded minor"
    - "tree projections and structural decomposition methods minimality and game theoretic characterization"
    - "on the computational complexity of a game of cops and robbers"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"
    - "hypertree decompositions and tractable queries"

Connected through hyperedge HE-8 (induced by source paper "hybrid v csps and algebraic reductions"):
  with members:
    - "algebraic properties of valued constraint satisfaction problem"
    - "the complexity of general valued csps"
    - "effectiveness of structural restrictions for hybrid csps"
    - "sherali adams relaxations for valued csps"
    - "the complexity of conservative valued csps"
    - "on the reduction of the csp dichotomy conjecture to digraphs"

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)