human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "approaching frac 3 2 for the s t path tsp"):
  Abstract: We show that there is a polynomial-time algorithm with approximation guarantee $\frac{3}{2}+\epsilon$ for the $s$-$t$-path TSP, for any fixed $\epsilon>0$. It is well known that Wolsey's analysis of Christofides' algorithm also works for the $s$-$t$-path TSP with its natural LP relaxation except for the narrow cuts (in which the LP solution has value less than two). A fixed optimum tour has either a single edge in a narrow cut (then call the edge and the cut lonely) or at least three (then call the cut busy). Our algorithm "guesses" (by dynamic programming) lonely cuts and edges. Then we partition the instance into smaller instances and strengthen the LP, requiring value at least three for busy cuts. By setting up a $k$-stage recursive dynamic program, we can compute a spanning tree $(V,S)$ and an LP solution $y$ such that $(\frac{1}{2}+O(2^{-k}))y$ is in the $T$-join polyhedron, where $T$ is the set of vertices whose degree in $S$ has the wrong parity. Our new algorithm does not imply an upper bound on the integrality ratio. However, we also show a smaller upper bound (less than 1.52) on the integrality ratio by a new analysis of the previously best algorithm, due to Seb\H{o} and van Zuylen.

Includes members:
  Member "a 1 5 approximation for path tsp":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "minimum scan cover with angular transition costs")
  Member "an improved upper bound on the integrality ratio for the s t path tsp":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "beating the integrality ratio for s t tours in graphs")
  Member "layers and matroids for the traveling salesman s paths":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "an improved upper bound on the integrality ratio for the s t path tsp")
  Member "better s t tours by gao trees":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "reducing path tsp to tsp")
  Member "reassembling trees for the traveling salesman":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "reducing path tsp to tsp")
  Member "improving christofides algorithm for the s t path tsp":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "reducing path tsp to tsp")

Question: Please tell me which class the source paper 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)