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: "verification of flat fifo systems"
  Abstract: The decidability and complexity of reachability problems and model-checking for flat counter systems have been explored in detail. However, only few results are known for flat FIFO systems, only in some particular cases (a single loop or a single bounded expression). We prove, by establishing reductions between properties, and by reducing SAT to a subset of these properties that many verification problems like reachability, non-termination, unboundedness are Np-complete for flat FIFO systems, generalizing similar existing results for flat counter systems. We construct a trace-flattable counter system that is bisimilar to a given flat FIFO system, which allows to model-check the original flat FIFO system. Our results lay the theoretical foundations and open the way to build a verification tool for (general) FIFO systems based on analysis of flat subsystems. 2012 ACM Subject Classification Theory of computation $\rightarrow$ Parallel computing models 1 Introduction FIFO systems Asynchronous distributed processes communicating through First In First Out (FIFO) channels are used since the seventies as models for protocols [40], distributed and concurrent programming and more recently for web service choreography interface [14]. Since FIFO systems simulate counter machines, most reachability properties are undecidable for FIFO systems: for example, the basic task of checking if the number of messages buffered in a channel can grow unboundedly is undecidable [13]. There aren't many interesting and useful FIFO subclasses with a decidable reachability problem. Considering FIFO systems with a unique FIFO channel is not a useful restriction since they may simulate Turing machines [13]. A few examples of decidable subclasses are half-duplex systems [15] (but they are restricted to two machines since the natural extension to three machines leads to undecidability), existentially bounded deadlock free FIFO systems [31] (but it is undecidable to check if a system is existentially bounded, even for deadlock free FIFO systems), synchronisable FIFO systems (the property of synchronisability is undecidable [28] and moreover, it is not clear which properties of synchronisable systems are decidable), flat FIFO systems [8, 9] and lossy FIFO systems [2] (but one loses the perfect FIFO mechanism).

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.CC(Computational Complexity)