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 "tree polymatrix games are ppad hard"):
  Abstract: We prove that it is PPAD-hard to compute a Nash equilibrium in a tree polymatrix game with twenty actions per player. This is the first PPAD hardness result for a game with a constant number of actions per player where the interaction graph is acyclic. Along the way we show PPAD-hardness for finding an $\epsilon$-fixed point of a 2D LinearFIXP instance, when $\epsilon$ is any constant less than $(\sqrt{2} - 1)/2 \approx 0.2071$. This lifts the hardness regime from polynomially small approximations in $k$-dimensions to constant approximations in two-dimensions, and our constant is substantial when compared to the trivial upper bound of $0.5$.

Includes members:
  Member "computing constrained approximate equilibria in polymatrix games":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "approximating the existential theory of the reals")
  Member "approximating nash equilibria in tree polymatrix games":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "approximating the existential theory of the reals")
  Member "an empirical study on computing equilibria in polymatrix games":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "nash equilibrium in smoothed polynomial time for network coordination games")
  Member "computing approximate nash equilibria in polymatrix games":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "graphical one sided markets")
  Member "settling the complexity of computing two player nash equilibria":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "learning zero sum simultaneous move markov games using function approximation and correlated equilibrium")

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.GT(Computer Science and Game Theory)