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: "efficient domination for some subclasses of p_6 free graphs in polynomial time"
  Abstract: Let $G$ be a finite undirected graph. A vertex {\em dominates} itself and all its neighbors in $G$. A vertex set $D$ is an {\em efficient dominating set} (\emph{e.d.}\ for short) of $G$ if every vertex of $G$ is dominated by exactly one vertex of $D$. The \emph{Efficient Domination} (ED) problem, which asks for the existence of an e.d.\ in $G$, is known to be \NP-complete even for very restricted graph classes such as $P_7$-free chordal graphs. The ED problem on a graph $G$ can be reduced to the Maximum Weight Independent Set (MWIS) problem on the square of $G$. The complexity of the ED problem is an open question for $P_6$-free graphs and was open even for the subclass of $P_6$-free chordal graphs. In this paper, we show that squares of $P_6$-free chordal graphs that have an e.d. are chordal; this even holds for the larger class of ($P_6$, house, hole, domino)-free graphs. This implies that ED/WeightedED is solvable in polynomial time for ($P_6$, house, hole, domino)-free graphs; in particular, for $P_6$-free chordal graphs. Moreover, based on our result that squares of $P_6$-free graphs that have an e.d. are hole-free and some properties concerning odd antiholes, we show that squares of ($P_6$, house)-free graphs (($P_6$, bull)-free graphs, respectively) that have an e.d. are perfect. This implies that ED/WeightedED is solvable in polynomial time for ($P_6$, house)-free graphs and for ($P_6$, bull)-free graphs (the time bound for ($P_6$, house, hole, domino)-free graphs is better than that for ($P_6$, house)-free graphs). The complexity of the ED problem for $P_6$-free graphs remains an open question.

Connected through hyperedge HE-1 (induced by source paper "on efficient domination for some classes of h free bipartite graphs"):
  with members:
    - "polynomial time algorithms for weighted efficient domination problems in at free graphs and dually chordal graphs"
    - "classifying the clique width of h free bipartite graphs"
    - "weighted efficient domination for p_5 kp_2 free graphs in polynomial time"
    - "the dilworth number of auto chordal bipartite graphs"
    - "new polynomial cases of the weighted efficient domination problem"
    - "efficient dominating and edge dominating sets for graphs and hypergraphs"

Connected through hyperedge HE-2 (induced by source paper "on efficient domination for some classes of h free chordal graphs"):
  with members:
    - "polynomial time algorithms for weighted efficient domination problems in at free graphs and dually chordal graphs"
    - "bounding the clique width of h free chordal graphs"
    - "weighted efficient domination for p_6 free graphs in polynomial time"
    - "weighted efficient domination for p_5 kp_2 free graphs in polynomial time"
    - "new polynomial cases of the weighted efficient domination problem"
    - "efficient dominating and edge dominating sets for graphs and hypergraphs"
    - "algorithms for unipolar and generalized split graphs"

Connected through hyperedge HE-3 (induced by source paper "weighted efficient domination for p_6 free graphs in polynomial time"):
  with members:
    - "independence and efficient domination on p_6 free graphs"
    - "weighted efficient domination for p 5 free graphs in linear time"
    - "weighted efficient domination for p_5 kp_2 free graphs in polynomial time"
    - "new polynomial cases of the weighted efficient domination problem"
    - "algorithms for unipolar and generalized split graphs"

Connected through hyperedge HE-4 (induced by source paper "weighted efficient domination for p 5 free graphs in linear time"):
  with members:
    - "independence and efficient domination on p_6 free graphs"
    - "weighted efficient domination for p_5 kp_2 free graphs in polynomial time"
    - "new polynomial cases of the weighted efficient domination problem"

Connected through hyperedge HE-5 (induced by source paper "independence and efficient domination on p_6 free graphs"):
  with members:
    - "weighted independent sets in a subclass of p_6 free graphs"

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)