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: "the certification problem format"
  Abstract: We provide an overview of CPF, the certification problem format, and explain some design decisions. Whereas CPF was originally invented to combine three different formats for termination proofs into a single one, in the meanwhile proofs for several other properties of term rewrite systems are also expressible: like confluence, complexity, and completion. As a consequence, the format is already supported by several tools and certifiers. Its acceptance is also demonstrated in international competitions: the certified tracks of both the termination and the confluence competition utilized CPF as exchange format between automated tools and trusted certifiers.

Connected through hyperedge HE-1 (induced by source paper "tools in term rewriting for education"):
  with members:
    - "nagoya termination tool"

Connected through hyperedge HE-2 (induced by source paper "optimizing a certified proof checker for a large scale computer generated proof"):
  with members:
    - "formalizing size optimal sorting networks extracting a certified proof checker"
    - "twenty five comparators is optimal when sorting nine inputs and twenty nine for ten"
    - "efficient generation of correctness certificates for the abstract domain of polyhedra"
    - "computer certified efficient exact reals in coq"
    - "certified exact transcendental real number computation in coq"

Connected through hyperedge HE-3 (induced by source paper "formalizing size optimal sorting networks extracting a certified proof checker"):
  with members:
    - "optimizing a certified proof checker for a large scale computer generated proof"
    - "twenty five comparators is optimal when sorting nine inputs and twenty nine for ten"
    - "efficient generation of correctness certificates for the abstract domain of polyhedra"

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)