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: "quality of local equilibria in discrete exchange economies"
  Abstract: This paper defines the notion of a local equilibrium of quality $(r , s)$, $0 \leq r , s$, in a discrete exchange economy: a partial allocation and item prices that guarantee certain stability properties parametrized by the numbers $r$ and $s$. The quality $( r , s )$ measures the fit between the allocation and the prices: the larger $r$ and $s$ the closer the fit. For $r , s \leq 1$ this notion provides a graceful degradation for the conditional equilibria of [10] which are exactly the local equilibria of quality $( 1 , 1 )$. For $1 < r , s $ the local equilibria of quality $( r , s )$ are {\em more stable} than conditional equilibria. Any local equilibrium of quality $( r , s )$ provides, without any assumption on the type of the agents' valuations, an allocation whose value is at least $\frac{r s} { 1 + r s }$ the optimal fractional allocation. In any economy in which all agents' valuations are $a$-submodular, i.e., exhibit complementarity bounded by $a \: \geq \: 1$, there is a local equilibrium of quality $( \frac{1} {a} , \frac{1}{a} )$. In such an economy any greedy allocation provides a local equilibrium of quality $( 1 , \frac{1}{a} ) $. Walrasian equilibria are not amenable to such graceful degradation.

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.GT(Computer Science and Game Theory)