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: "on the identity problem for the special linear group and the heisenberg group"
  Abstract: We study the identity problem for matrices, i.e., whether the identity matrix is in a semigroup generated by a given set of generators. In particular we consider the identity problem for the special linear group following recent NP-completeness result for ${\rm SL}(2,\mathbb{Z})$ and the undecidability for ${\rm SL}(4,\mathbb{Z})$ generated by $48$ matrices. First we show that there is no embedding from pairs of words into $3\times3$ integer matrices with determinant one, i.e., into ${\rm SL}(3,\mathbb{Z})$ extending previously known result that there is no embedding into $\mathbb{C}^{2\times 2}$. Apart from theoretical importance of the result it can be seen as a strong evidence that the computational problems in \slthreez are decidable. The result excludes the most natural possibility of encoding the Post correspondence problem into ${\rm SL}(3,\mathbb{Z})$, where the matrix products extended by the right multiplication correspond to the Turing machine simulation. Then we show that the identity problem is decidable in polynomial time for an important subgroup of ${\rm SL}(3,\mathbb{Z})$, the Heisenberg group ${\rm H}(3,\mathbb{Z})$. Furthermore, we extend the decidability result for ${\rm H}(n,\mathbb{Q})$ in any dimension $n$. Finally we are tightening the gap on decidability question for this long standing open problem by improving the undecidability result for the identity problem in ${\rm SL}(4,\mathbb{Z})$ substantially reducing the bound on the size of the generator set from $48$ to $8$ by developing a novel reduction technique.

Connected through hyperedge HE-1 (induced by source paper "extended models of finite automata"):
  with members:
    - "on reachability problems for low dimensional matrix semigroups"
    - "extended finite automata and decision problems for matrix semigroups"
    - "generalized results on monoids as memory"
    - "language classes associated with automata over matrix groups"
    - "homing vector automata"
    - "silent transitions in automata with storage"
    - "real time vector automata"
    - "on the capabilities of grammars automata and transducers controlled by monoids"

Connected through hyperedge HE-2 (induced by source paper "on the mortality problem from multiplicative matrix equations to linear recurrence sequences and beyond"):
  with members:
    - "solvability of matrix exponential equations"
    - "on the skolem problem for continuous linear dynamical systems"
    - "on termination of integer linear loops"
    - "tighter undecidability bounds for matrix mortality zero in the corner problems and more"
    - "on the positivity problem for simple linear recurrence sequences"
    - "on the complexity of the orbit problem"
    - "positivity problems for low order linear recurrence sequences"

Connected through hyperedge HE-3 (induced by source paper "on reachability problems for low dimensional matrix semigroups"):
  with members:
    - "polynomial invariants for affine programs"
    - "tighter undecidability bounds for matrix mortality zero in the corner problems and more"
    - "positivity problems for low order linear recurrence sequences"

Connected through hyperedge HE-4 (induced by source paper "decidability of membership problems for flat rational subsets of mathrm gl 2 mathbb q and singular matrices"):
  with members:
    - "on the mortality problem from multiplicative matrix equations to linear recurrence sequences and beyond"
    - "tighter undecidability bounds for matrix mortality zero in the corner problems and more"

Connected through hyperedge HE-5 (induced by source paper "decidability of the mortality problem from multiplicative matrix equations to linear recurrence sequences and beyond"):
  with members:
    - "solvability of matrix exponential equations"
    - "on termination of integer linear loops"

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.DM(Discrete Mathematics)