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: "the mathematics of xenology di cographs symbolic ultrametrics 2 structures and tree representable systems of binary relations"
  Abstract: The concepts of orthology, paralogy, and xenology play a key role in molecular evolution. Orthology and paralogy distinguish whether a pair of genes originated by speciation or duplication. The corresponding binary relations on a set of genes form complementary cographs. Allowing more than two types of ancestral event types leads to symmetric symbolic ultrametrics. Horizontal gene transfer, which leads to xenologous gene pairs, however, is inherent asymmetric since one offspring copy "jumps" into another genome, while the other continues to be inherited vertically. We therefore explore here the mathematical structure of the non-symmetric generalization of symbolic ultrametrics. Our main results tie non-symmetric ultrametrics together with di-cographs (the directed generalization of cographs), so-called uniformly non-prime 2-structures, and hierarchical structures on the set of strong modules. This yields a characterization of relation structures that can be explained in terms of trees and types of ancestral events. This framework accommodates a horizontal-transfer relation in terms of an ancestral event and thus, is slightly different from the the most commonly used definition of xenology.

Connected through hyperedge HE-1 (induced by source paper "generalized fitch graphs iii symmetrized fitch maps and sets of symmetric binary relations that are explained by unrooted edge labeled trees"):
  with members:
    - "generalized fitch graphs ii sets of binary relations that are explained by edge labeled trees"
    - "generalized fitch graphs edge labeled graphs that are explained by edge labeled trees"
    - "reconstructing gene trees from fitch s xenology relation"

Connected through hyperedge HE-2 (induced by source paper "generalized fitch graphs ii sets of binary relations that are explained by edge labeled trees"):
  with members:
    - "generalized fitch graphs iii symmetrized fitch maps and sets of symmetric binary relations that are explained by unrooted edge labeled trees"
    - "generalized fitch graphs edge labeled graphs that are explained by edge labeled trees"
    - "reconstructing gene trees from fitch s xenology relation"
    - "beyond representing orthology relations by trees"
    - "phylogenomics with paralogs"

Connected through hyperedge HE-3 (induced by source paper "reconstruction of time consistent species trees"):
  with members:
    - "from event labeled gene trees to species trees"
    - "reconstructing gene trees from fitch s xenology relation"
    - "phylogenomics with paralogs"

Connected through hyperedge HE-4 (induced by source paper "generalized fitch graphs edge labeled graphs that are explained by edge labeled trees"):
  with members:
    - "a short note on undirected fitch graphs"
    - "reconstructing gene trees from fitch s xenology relation"
    - "phylogenomics with paralogs"

Connected through hyperedge HE-5 (induced by source paper "cograph editing merging modules is equivalent to editing p4 s"):
  with members:
    - "exact and heuristic algorithms for cograph editing"
    - "reconstructing gene trees from fitch s xenology relation"
    - "partial homology relations satisfiability in terms of di cographs"
    - "phylogenomics with paralogs"
    - "on symbolic ultrametrics cotree representations and cograph edge decompositions and partitions"
    - "on tree representations of relations and graphs symbolic ultrametrics and cograph edge decompositions"
    - "parameterized algorithms for modular width"
    - "on the non existence of polynomial kernels for p l free edge modification problems"

Connected through hyperedge HE-6 (induced by source paper "forbidden time travel characterization of time consistent tree reconciliation maps"):
  with members:
    - "from event labeled gene trees to species trees"
    - "from event labeled gene trees with horizontal gene transfer to species trees"
    - "phylogenomics with paralogs"
    - "on symbolic ultrametrics cotree representations and cograph edge decompositions and partitions"
    - "on tree representations of relations and graphs symbolic ultrametrics and cograph edge decompositions"

Connected through hyperedge HE-7 (induced by source paper "reconstructing gene trees from fitch s xenology relation"):
  with members:
    - "generalized fitch graphs edge labeled graphs that are explained by edge labeled trees"
    - "from event labeled gene trees to species trees"
    - "partial homology relations satisfiability in terms of di cographs"
    - "phylogenomics with paralogs"
    - "on tree representations of relations and graphs symbolic ultrametrics and cograph edge decompositions"

Connected through hyperedge HE-8 (induced by source paper "from event labeled gene trees to species trees"):
  with members:
    - "phylogenomics with paralogs"
    - "on tree representations of relations and graphs symbolic ultrametrics and cograph edge decompositions"

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)