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: "tighter undecidability bounds for matrix mortality zero in the corner problems and more"
  Abstract: We study the decidability of three well-known problems related to integer matrix multiplication: Mortality (M), Zero in the Left-Upper Corner (Z), and Zero in the Right-Upper Corner (R). Let d and k be positive integers. Define M d (k) as the following special case of the Mortality problem: given a set X of d-by-d integer matrices such that the cardinality of X is not greater than k, decide whether the d-by-d zero matrix belongs to X + , where X + denotes the closure of X under the usual matrix multiplication. In the same way, define the Z d (k) problem as: given an instance X of M d (k) (the instances of Z d (k) are the same as those of M d (k)), decide whether at least one matrix in X + has a zero in the left-upper corner. Define R d (k) as the variant of Z d (k) where “left-upper corner” is replaced with “right-upper corner”. In the paper, we prove that M 3 (6), M 5 (4), M 9 (3), M 15 (2), Z 3 (5), Z 5 (3), Z 9 (2), R 3 (6), R 4 (5), and R 6 (3) are undecidable. The previous best comparable results were the undecidabilities of M 3 (7), M 13 (3), M 21 (2), Z 3 (7), Z 13 (2), R 3 (7), and R 10 (2).

Connected through hyperedge HE-1 (induced by source paper "on the mortality problem from multiplicative matrix equations to linear recurrence sequences and beyond"):
  with members:
    - "on the identity problem for the special linear group and the heisenberg group"
    - "solvability of matrix exponential equations"
    - "on the skolem problem for continuous linear dynamical systems"
    - "on termination of integer linear loops"
    - "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-2 (induced by source paper "on reachability problems for low dimensional matrix semigroups"):
  with members:
    - "polynomial invariants for affine programs"
    - "on the identity problem for the special linear group and the heisenberg group"
    - "positivity problems for low order linear recurrence sequences"

Connected through hyperedge HE-3 (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"
    - "on the identity problem for the special linear group and the heisenberg group"

Connected through hyperedge HE-4 (induced by source paper "decidability of the membership problem for 2 times 2 integer matrices"):
  with members:
    - "on the positivity problem for simple linear recurrence sequences"
    - "on the complexity of the orbit problem"
    - "ultimate positivity is decidable for simple linear recurrence sequences"

Connected through hyperedge HE-5 (induced by source paper "undecidable cases of model checking probabilistic temporal epistemic logic extended abstract"):
  with members:
    - "positivity problems for low order linear recurrence sequences"

Connected through hyperedge HE-6 (induced by source paper "undecidable cases of model checking probabilistic temporal epistemic logic"):
  with members:
    - "positivity problems for low order linear recurrence sequences"

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)