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 solving boolean multilevel optimization problems"
  Abstract: Many combinatorial optimization problems entail a number of hierarchically dependent optimization problems. An often used solution is to associate a suitably large cost with each individual optimization problem, such that the solution of the resulting aggregated optimization problem solves the original set of hierarchically dependent optimization problems. This paper starts by studying the package upgradeability problem in software distributions. Straightforward solutions based on Maximum Satisfiability (MaxSAT) and pseudo-Boolean (PB) optimization are shown to be ineffective, and unlikely to scale for large problem instances. Afterwards, the package upgradeability problem is related to multilevel optimization. The paper then develops new algorithms for Boolean Multilevel Optimization (BMO) and highlights a large number of potential applications. The experimental results indicate that the proposed algorithms for BMO allow solving optimization problems that existing MaxSAT and PB solvers would otherwise be unable to solve.

Connected through hyperedge HE-1 (induced by source paper "anytime answer set optimization via unsatisfiable core shrinking"):
  with members:
    - "complexity and compilation of gz aggregates in answer set programming"
    - "rewriting recursive aggregates in answer set programming back to monotonicity"
    - "anytime computation of cautious consequences in answer set programming"
    - "vicious circle principle and logic programs with aggregates"
    - "complex optimization in answer set programming"
    - "algorithms for weighted boolean optimization"
    - "logic programs with propositional connectives and aggregates"

Connected through hyperedge HE-2 (induced by source paper "aligning component upgrades"):
  with members:
    - "handling software upgradeability problems with milp solvers"
    - "solving linux upgradeability problems using boolean optimization"
    - "package upgrades in foss distributions details and challenges"

Connected through hyperedge HE-3 (induced by source paper "solving linux upgradeability problems using boolean optimization"):
  with members:
    - "handling software upgradeability problems with milp solvers"
    - "algorithms for weighted boolean optimization"

Connected through hyperedge HE-4 (induced by source paper "handling software upgradeability problems with milp solvers"):
  with members:
    - "algorithms for weighted boolean optimization"

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.LO(Logic in Computer Science)