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: "are there any good digraph width measures"
  Abstract: Several width measures for digraphs have been proposed in the last few years. However, none of them possess all the “nice” properties of treewidth, namely, (1) being algorithmically useful, that is, admitting polynomial-time algorithms for a large class of problems on digraphs of bounded width; and (2) having nice structural properties such as being monotone under taking subdigraphs and some form of arc contractions. As for (1), MSO1 is the least common denominator of all reasonably expressive logical languages that can speak about the edge/arc relation on the vertex set, and so it is quite natural to demand efficient solvability of all MSO1-definable problems in this context. (2) is a necessary condition for a width measure to be characterizable by some version of the cops-and-robber game characterizing treewidth. More specifically, we introduce a notion of a directed topological minor and argue that it is the weakest useful notion of minors for digraphs in this context. Our main result states that any reasonable digraph measure that is algorithmically useful and structurally nice cannot be substantially different from the treewidth of the underlying undirected graph.

Connected through hyperedge HE-1 (induced by source paper "width parameterizations for knot free vertex deletion on digraphs"):
  with members:
    - "an algorithmic metatheorem for directed treewidth"
    - "subgraphs satisfying mso properties on z topologically orderable digraphs"
    - "digraph complexity measures and applications in formal language theory"
    - "the combinatorics of resource sharing"

Connected through hyperedge HE-2 (induced by source paper "tractable lineages on treelike instances limits and extensions"):
  with members:
    - "provenance circuits for trees and treelike instances extended version"
    - "approximate lifted inference with probabilistic databases"
    - "polynomial bounds for the grid minor theorem"
    - "complexity of inference in graphical models"
    - "lower bounds for the complexity of monadic second order logic"
    - "algorithmic meta theorems"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"
    - "the dichotomy of conjunctive queries on probabilistic structures"

Connected through hyperedge HE-3 (induced by source paper "directed multicut is w 1 hard even for four terminal pairs"):
  with members:
    - "half integrality lp branching and fpt algorithms"
    - "list h coloring a graph by removing few vertices"
    - "minimum bisection is fixed parameter tractable"
    - "designing fpt algorithms for cut problems using randomized contractions"
    - "faster parameterized algorithms using linear programming"
    - "fixed parameter tractability of multicut in directed acyclic graphs"
    - "finding small separators in linear time via treewidth reduction"
    - "clique cover and graph separation new incompressibility results"

Connected through hyperedge HE-4 (induced by source paper "an algorithmic metatheorem for directed treewidth"):
  with members:
    - "subgraphs satisfying mso properties on z topologically orderable digraphs"
    - "digraph complexity measures and applications in formal language theory"
    - "on complexity of minimum leaf out branching problem"

Connected through hyperedge HE-5 (induced by source paper "the rank width of edge coloured graphs"):
  with members:
    - "better algorithms for satisfiability problems for formulas of bounded rank width"
    - "partitions versus sets a case of duality"
    - "monadic second order model checking on decomposable matroids"
    - "on the expressive power of permanents and perfect matchings of matrices of bounded pathwidth cliquewidth"

Connected through hyperedge HE-6 (induced by source paper "subgraphs satisfying mso properties on z topologically orderable digraphs"):
  with members:
    - "on the parameterized intractability of monadic second order logic"
    - "digraph complexity measures and applications in formal language theory"
    - "lower bounds for the complexity of monadic second order logic"

Connected through hyperedge HE-7 (induced by source paper "the planar directed k vertex disjoint paths problem is fixed parameter tractable"):
  with members:
    - "finding topological subgraphs is fixed parameter tractable"
    - "digraph decompositions and monotonicity in digraph searching"

Connected through hyperedge HE-8 (induced by source paper "jungles bundles and fixed parameter tractability"):
  with members:
    - "bidimensionality and kernels"
    - "the rank width of edge coloured graphs"
    - "designing fpt algorithms for cut problems using randomized contractions"
    - "bidimensionality and eptas"
    - "finding topological subgraphs is fixed parameter tractable"
    - "kernels for feedback arc set in tournaments"
    - "computing crossing numbers in quadratic time"

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.DM(Discrete Mathematics)