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 counting untyped lambda terms"
  Abstract: We present several results on counting untyped lambda terms, i.e., on telling how many terms belong to such or such class, according to the size of the terms and/or to the number of free variables.

Connected through hyperedge HE-1 (induced by source paper "quantitative aspects of linear and affine closed lambda terms"):
  with members:
    - "linear lambda terms as invariants of rooted trivalent maps"
    - "a natural counting of lambda terms"
    - "counting and generating terms in the binary lambda calculus extended version"
    - "counting isomorphism classes of β normal linear lambda terms"
    - "a correspondence between rooted planar maps and normal planar lambda terms"
    - "boltzmann samplers for random generation of lambda terms"
    - "counting and generating lambda terms"
    - "how big is bci fragment of bck logic"

Connected through hyperedge HE-2 (induced by source paper "on uniquely closable and uniquely typable skeletons of lambda terms"):
  with members:
    - "counting and generating terms in the binary lambda calculus extended version"
    - "counting and generating lambda terms"

Connected through hyperedge HE-3 (induced by source paper "skeletal program enumeration for rigorous compiler testing"):
  with members:
    - "counting and generating terms in the binary lambda calculus extended version"
    - "counting and generating lambda terms"

Connected through hyperedge HE-4 (induced by source paper "counting and generating terms in the binary lambda calculus extended version"):
  with members:
    - "counting terms in the binary lambda calculus"
    - "efficient random sampling of binary and unary binary trees via holonomic equations"
    - "generalizing determinization from automata to coalgebras"
    - "counting and generating lambda terms"

Connected through hyperedge HE-5 (induced by source paper "boltzmann samplers for random generation of lambda terms"):
  with members:
    - "counting terms in the binary lambda calculus"
    - "efficient random sampling of binary and unary binary trees via holonomic equations"
    - "an exercise on streams convergence acceleration"
    - "counting and generating lambda terms"

Connected through hyperedge HE-6 (induced by source paper "counting terms in the binary lambda calculus"):
  with members:
    - "counting and generating lambda terms"

Connected through hyperedge HE-7 (induced by source paper "counting and generating lambda terms"):
  with members:
    - "introduction to linear logic and ludics part ii"

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)