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: "set theory for verification ii induction and recursion"
  Abstract: A theory of recursive definitions has been mechanized in Isabelle's Zermelo-Fraenkel (ZF) set theory. The objective is to support the formalization of particular recursive definitions for use in verification, semantics proofs and other computational reasoning. Inductively defined sets are expressed as least fixedpoints, applying the Knaster-Tarski Theorem over a suitable set. Recursive functions are defined by well-founded recursion and its derivatives, such as transfinite recursion. Recursive data structures are expressed by applying the Knaster-Tarski Theorem to a set, such as V[omega], that is closed under Cartesian product and disjoint sum. Worked examples include the transitive closure of a relation, lists, variable-branching trees and mutually recursive trees and forests. The Schr\"oder-Bernstein Theorem and the soundness of propositional logic are proved in Isabelle sessions.

Connected through hyperedge HE-1 (induced by source paper "mutual coinduction"):
  with members:
    - "java generics an order theoretic approach abridged outline"
    - "induction coinduction and fixed points intuitions and tutorial"
    - "induction coinduction and fixed points in pl type theory"
    - "induction coinduction and fixed points a concise comparative survey"
    - "object oriented theorem proving ootp first thoughts"

Connected through hyperedge HE-2 (induced by source paper "first steps towards a formalization of forcing"):
  with members:
    - "formalization of the fundamental group in untyped set theory using auto2"

Connected through hyperedge HE-3 (induced by source paper "formalization of the fundamental group in untyped set theory using auto2"):
  with members:
    - "auto2 a saturation based heuristic prover for higher order logic"
    - "set theory for verification i from foundations to functions"

Connected through hyperedge HE-4 (induced by source paper "foundational extensible corecursion"):
  with members:
    - "programming and reasoning with guarded recursion for coinductive types"
    - "co recursion in logic programming lazy vs eager"
    - "abstract gsos rules and a modular treatment of recursive definitions"
    - "parametricity in an impredicative sort"
    - "miniagda integrating sized and dependent types"
    - "a formally verified compiler back end"
    - "set theory for verification i from foundations to functions"

Connected through hyperedge HE-5 (induced by source paper "bootstrapping inductive and coinductive types in hascasl"):
  with members:
    - "mechanizing coinduction and corecursion in higher order logic"

Connected through hyperedge HE-6 (induced by source paper "set theory for verification i from foundations to functions"):
  with members:
    - "the foundation of a generic theorem prover"
    - "isabelle the next 700 theorem provers"

Connected through hyperedge HE-7 (induced by source paper "mechanizing coinduction and corecursion in higher order logic"):
  with members:
    - "a concrete final coalgebra theorem for zf set theory"
    - "the foundation of a generic theorem prover"

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)