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: "colouring diamond free graphs"
  Abstract: The Colouring problem is that of deciding, given a graph $G$ and an integer $k$, whether $G$ admits a (proper) $k$-colouring. For all graphs $H$ up to five vertices, we classify the computational complexity of Colouring for $(\mbox{diamond},H)$-free graphs. Our proof is based on combining known results together with proving that the clique-width is bounded for $(\mbox{diamond}, P_1+2P_2)$-free graphs. Our technique for handling this case is to reduce the graph under consideration to a $k$-partite graph that has a very specific decomposition. As a by-product of this general technique we are also able to prove boundedness of clique-width for four other new classes of $(H_1,H_2)$-free graphs. As such, our work also continues a recent systematic study into the (un)boundedness of clique-width of $(H_1,H_2)$-free graphs, and our five new classes of bounded clique-width reduce the number of open cases from 13 to 8.

Connected through hyperedge HE-1 (induced by source paper "theta triangle free and even hole k 4 free graphs part 2 bounds on treewidth"):
  with members:
    - "polynomial time algorithm for maximum weight independent set on p_6 free graphs"
    - "on the structure of pan even hole free graphs"
    - "maximum weight independent sets for p_7 triangle free graphs in polynomial time"
    - "clique width of graph classes defined by two forbidden induced subgraphs"

Connected through hyperedge HE-2 (induced by source paper "graph isomorphism for h_1 h_2 free graphs an almost complete dichotomy"):
  with members:
    - "canonisation and definability for graphs of bounded rank width"
    - "an improved isomorphism test for bounded tree width graphs"
    - "a faster isomorphism test for graphs of small degree"
    - "clique width for graph classes closed under complementation"
    - "graph isomorphism for unit square graphs"
    - "induced minor free graphs isomorphism and clique width"
    - "bounding the clique width of h free chordal graphs"
    - "isomorphism testing for graphs of bounded rank width"

Connected through hyperedge HE-3 (induced by source paper "clique width for graph classes closed under complementation"):
  with members:
    - "the behavior of clique width under graph operations and graph transformations"
    - "hereditary graph classes when the complexities of colouring and clique cover coincide"
    - "bounding the clique width of h free chordal graphs"
    - "isomorphism testing for graphs of bounded rank width"
    - "bounding the clique width of h free split graphs"
    - "bounding clique width via perfect graphs"
    - "clique width of graph classes defined by two forbidden induced subgraphs"
    - "classifying the clique width of h free bipartite graphs"

Connected through hyperedge HE-4 (induced by source paper "on colouring 2p_2 h free and p_5 h free graphs"):
  with members:
    - "solving the clique cover problem on bull c_4 free graphs"
    - "hereditary graph classes when the complexities of colouring and clique cover coincide"
    - "complexity of coloring graphs without paths and cycles"
    - "the coloring problem for classes with two small obstructions"

Connected through hyperedge HE-5 (induced by source paper "hereditary graph classes when the complexities of colouring and clique cover coincide"):
  with members:
    - "clique width for graph classes closed under complementation"
    - "solving the clique cover problem on bull c_4 free graphs"
    - "classifying the clique width of h free bipartite graphs"
    - "complexity of coloring graphs without paths and cycles"
    - "the coloring problem for classes with two small obstructions"

Connected through hyperedge HE-6 (induced by source paper "bounded clique width of s_ 1 2 2 triangle free graphs"):
  with members:
    - "classifying the clique width of h free bipartite graphs"

Connected through hyperedge HE-7 (induced by source paper "bounding the clique width of h free chordal graphs"):
  with members:
    - "the behavior of clique width under graph operations and graph transformations"
    - "isomorphism testing for graphs of bounded rank width"
    - "bounding the clique width of h free split graphs"
    - "bounding clique width via perfect graphs"
    - "clique width of graph classes defined by two forbidden induced subgraphs"
    - "classifying the clique width of h free bipartite graphs"
    - "towards an isomorphism dichotomy for hereditary graph classes"
    - "a sat approach to clique width"

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)