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: "a sat attack on the erdos discrepancy conjecture"
  Abstract: In 1930s Paul Erdos conjectured that for any positive integer C in any infinite +1 -1 sequence (x_n) there exists a subsequence x_d, x_{2d}, ... , x_{kd} for some positive integers k and d, such that |x_d + x_{2d} + ... + x_{kd}|> C. The conjecture has been referred to as one of the major open problems in combinatorial number theory and discrepancy theory. For the particular case of C=1 a human proof of the conjecture exists; for C=2 a bespoke computer program had generated sequences of length 1124 having discrepancy 2, but the status of the conjecture remained open even for such a small bound. We show that by encoding the problem into Boolean satisfiability and applying the state of the art SAT solvers, one can obtain a sequence of length 1160 with discrepancy 2 and a proof of the Erdos discrepancy conjecture for C=2, claiming that no sequence of length 1161 and discrepancy 2 exists. We also present our partial results for the case of C=3.

Connected through hyperedge HE-1 (induced by source paper "applying computer algebra systems with sat solvers to the williamson conjecture"):
  with members:
    - "enumeration of complex golay pairs via programmatic sat"
    - "a sat cas approach to finding good matrices new examples and counterexamples"
    - "schur number five"
    - "solving and verifying the boolean pythagorean triples problem via cube and conquer"

Connected through hyperedge HE-2 (induced by source paper "optimal bounds for the no show paradox via sat solving"):
  with members:
    - "solving and verifying the boolean pythagorean triples problem via cube and conquer"
    - "welfare maximization entices participation"
    - "automated reasoning in social choice theory some remarks"
    - "complexity of mechanism design"
    - "automated search for impossibility theorems in social choice theory ranking sets of objects"
    - "set monotonicity implies kelly strategyproofness"
    - "equilibria of plurality voting with abstentions"

Connected through hyperedge HE-3 (induced by source paper "the packing chromatic number of the infinite square lattice is between 13 and 15"):
  with members:
    - "subdivision into i packings and s packing chromatic number of some lattices"
    - "a new lower bound for the ramsey number r 4 8"
    - "the packing chromatic number of the square lattice is at least 12"

Connected through hyperedge HE-4 (induced by source paper "computer aided proof of erdos discrepancy properties"):
  with members:
    - "on the erdos discrepancy problem"
    - "optimal private halfspace counting via discrepancy"

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)