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: "computing the ramsey number r 4 3 3 using abstraction and symmetry breaking"
  Abstract: The number $R(4,3,3)$ is often presented as the unknown Ramsey number with the best chances of being found "soon". Yet, its precise value has remained unknown for almost 50 years. This paper presents a methodology based on \emph{abstraction} and \emph{symmetry breaking} that applies to solve hard graph edge-coloring problems. The utility of this methodology is demonstrated by using it to compute the value $R(4,3,3)=30$. Along the way it is required to first compute the previously unknown set ${\cal R}(3,3,3;13)$ consisting of 78{,}892 Ramsey colorings.

Connected through hyperedge HE-1 (induced by source paper "a nonexistence certificate for projective planes of order ten with weight 15 codewords"):
  with members:
    - "sat solvers and computer algebra systems a powerful combination for mathematics"
    - "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"
    - "computer aided proof of erdos discrepancy properties"
    - "practical graph isomorphism ii"
    - "green tao numbers and sat"

Connected through hyperedge HE-2 (induced by source paper "optimal depth sorting networks"):
  with members:
    - "sorting networks to the end and back again"
    - "solving and verifying the boolean pythagorean triples problem via cube and conquer"
    - "new bounds on optimal sorting networks"
    - "applying sorting networks to synthesize optimized sorting libraries"
    - "sorting networks the end game"
    - "the quest for optimal sorting networks efficient generation of two layer prefixes"
    - "twenty five comparators is optimal when sorting nine inputs and twenty nine for ten"
    - "computer aided proof of erdos discrepancy properties"

Connected through hyperedge HE-3 (induced by source paper "exploring the use of shatter for allsat through ramsey type problems"):
  with members:
    - "on local domain symmetry for model expansion"
    - "breaking symmetries in graph search with canonizing sets"
    - "practical graph isomorphism ii"
    - "symmetry breaking constraints recent results"

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.AI(Artificial Intelligence)