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 triangles and cross free convexity in discrete optimisation"
  Abstract: The minimisation problem of a sum of unary and pairwise functions of discrete variables is a general NP-hard problem with wide applications such as computing MAP configurations in Markov Random Fields (MRF), minimising Gibbs energy, or solving binary Valued Constraint Satisfaction Problems (VCSPs).#R##N##R##N#We study the computational complexity of classes of discrete optimisation problems given by allowing only certain types of costs in every triangle of variable-value assignments to three distinct variables. We show that for several computational problems, the only non-trivial tractable classes are the well known maximum matching problem and the recently discovered joint-winner property. Our results, apart from giving complete classifications in the studied cases, provide guidance in the search for hybrid tractable classes; that is, classes of problems that are not captured by restrictions on the functions (such as submodularity) or the structure of the problem graph (such as bounded treewidth).#R##N##R##N#Furthermore, we introduce a class of problems with convex cardinality functions on cross-free sets of assignments. We prove that while imposing only one of the two conditions renders the problem NP-hard, the conjunction of the two gives rise to a novel tractable class satisfying the cross-free convexity property, which generalises the joint-winner property to problems of unbounded arity.

Connected through hyperedge HE-1 (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 optimization problems through hypergraph based structural restrictions"
    - "hybrid tractability of valued constraint problems"

Connected through hyperedge HE-2 (induced by source paper "discrete convexity in joint winner property"):
  with members:
    - "hybrid tractability of valued constraint problems"

Connected through hyperedge HE-3 (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"
    - "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"
    - "the power of linear programming for valued csps a constructive characterization"

Connected through hyperedge HE-4 (induced by source paper "variable and value elimination in binary constraint satisfaction via forbidden patterns"):
  with members:
    - "a dichotomy for 2 constraint forbidden csp patterns"
    - "the tractability of csp classes defined by forbidden patterns"
    - "hybrid tractable classes of binary quantified constraint satisfaction problems"
    - "conflict directed backjumping revisited"

Connected through hyperedge HE-5 (induced by source paper "the complexity of conservative valued csps"):
  with members:
    - "constraint solving via fractional edge covers"
    - "the complexity of approximating conservative counting csps"
    - "the power of linear programming for valued csps"
    - "tractable optimization problems through hypergraph based structural restrictions"
    - "the power of linear programming for valued csps a constructive characterization"
    - "extensions of the minimum cost homomorphism problem"
    - "min csp on four elements moving beyond submodularity"
    - "hybrid tractability of valued constraint problems"

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.CC(Computational Complexity)