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: "decidability of membership problems for flat rational subsets of mathrm gl 2 mathbb q and singular matrices"
  Abstract: In this work we extend previously known decidability results for $2\times 2$ matrices over $\mathbb{Q}$. Namely, we introduce a notion of flat rational sets: if $M$ is a monoid and $N\leq M$ is its submonoid, then flat rational sets of $M$ relative to $N$ are finite unions of the form $L_0g_1L_1 \cdots g_t L_t$ where all $L_i$s are rational subsets of $N$ and $g_i\in M$. We give quite general sufficient conditions under which flat rational sets form an effective relative Boolean algebra. As a corollary, we obtain that the emptiness problem for Boolean combinations of flat rational subsets of $\mathrm{GL}(2,\mathbb{Q})$ over $\mathrm{GL}(2,\mathbb{Z})$ is decidable. #R##N#We also show a dichotomy for nontrivial group extension of $\mathrm{GL}(2,\mathbb{Z})$ in $\mathrm{GL}(2,\mathbb{Q})$: if $G$ is a f.g. group such that $\mathrm{GL}(2,\mathbb{Z}) < G \leq \mathrm{GL}(2,\mathbb{Q})$, then either $G\cong \mathrm{GL}(2,\mathbb{Z})\times \mathbb{Z}^k$, for some $k\geq 1$, or $G$ contains an extension of the Baumslag-Solitar group $\mathrm{BS}(1,q)$, with $q\geq2$, of infinite index. It turns out that in the first case the membership problem for $G$ is decidable but the equality problem for rational subsets of $G$ is undecidable. In the second case, the membership problem for $G$ is an open problem as it is open for $\mathrm{BS}(1,q)$. #R##N#In the last section we prove new decidability results for flat rational sets that contain singular matrices. In particular, we show that the membership problem is decidable for flat rational subsets of $M(2,\mathbb{Q})$ relative to the submonoid that is generated by the matrices from $M(2,\mathbb{Z})$ with determinants $0,\pm1$ and the central rational matrices.

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.FL(Formal Languages and Automata Theory)