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: "complexity of fractran and productivity"
  Abstract: In functional programming languages the use of infinite structures is common practice. For total correctness of programs dealing with infinite structures one must guarantee that every finite part of the result can be evaluated in finitely many steps. This is known as productivity. For programming with infinite structures, productivity is what termination in well-defined results is for programming with finite structures. #R##N#Fractran is a simple Turing-complete programming language invented by Conway. We prove that the question whether a Fractran program halts on all positive integers is Pi^0_2-complete. In functional programming, productivity typically is a property of individual terms with respect to the inbuilt evaluation strategy. By encoding Fractran programs as specifications of infinite lists, we establish that this notion of productivity is Pi^0_2-complete even for the most simple specifications. Therefore it is harder than termination of individual terms. In addition, we explore possible generalisations of the notion of productivity in the framework of term rewriting, and prove that their computational complexity is Pi^1_1-complete, thus exceeding the expressive power of first-order logic.

Connected through hyperedge HE-1 (induced by source paper "star games and hydras"):
  with members:
    - "local termination theory and practice"

Connected through hyperedge HE-2 (induced by source paper "coinductive foundations of infinitary rewriting and infinitary equational logic"):
  with members:
    - "local termination theory and practice"

Connected through hyperedge HE-3 (induced by source paper "a coinductive framework for infinitary rewriting and equational reasoning extended version"):
  with members:
    - "coinductive techniques in infinitary lambda calculus"
    - "infinitary term rewriting for weakly orthogonal systems properties and counterexamples"
    - "a coinductive treatment of infinitary rewriting"
    - "local termination theory and practice"

Connected through hyperedge HE-4 (induced by source paper "on periodically iterated morphisms"):
  with members:
    - "automatic sequences and zip specifications"
    - "sequences close to periodic"
    - "data oblivious stream productivity"

Connected through hyperedge HE-5 (induced by source paper "on the complexity of equivalence of specifications of infinite objects"):
  with members:
    - "automatic sequences and zip specifications"
    - "data oblivious stream productivity"

Connected through hyperedge HE-6 (induced by source paper "productivity of non orthogonal term rewrite systems"):
  with members:
    - "stream productivity by outermost termination"
    - "data oblivious stream productivity"

Connected through hyperedge HE-7 (induced by source paper "automatic sequences and zip specifications"):
  with members:
    - "data oblivious stream productivity"

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)