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: "nominal logic programming"
  Abstract: Nominal logic is an extension of first-order logic which provides a simple foundation for formalizing and reasoning about abstract syntax modulo consistent renaming of bound names (that is, alpha-equivalence). This article investigates logic programming based on nominal logic. We describe some typical nominal logic programs, and develop the model-theoretic, proof-theoretic, and operational semantics of such programs. Besides being of interest for ensuring the correct behavior of implementations, these results provide a rigorous foundation for techniques for analysis and reasoning about nominal logic programs, as we illustrate via examples.

Connected through hyperedge HE-1 (induced by source paper "beyond sets with atoms definability in first order logic"):
  with members:
    - "single use register automata for data words"
    - "smt solving for functional programming over infinite structures"
    - "automata theory in nominal sets"

Connected through hyperedge HE-2 (induced by source paper "on nominal syntax and permutation fixed points"):
  with members:
    - "nominal c unification"
    - "nominal unification of higher order expressions with recursive let"
    - "nominal unification from a higher order perspective"

Connected through hyperedge HE-3 (induced by source paper "advances in property based testing for alpha prolog"):
  with members:
    - "a framework for proof certificates in finite state exploration"
    - "a bi directional refinement algorithm for the calculus of co inductive constructions"
    - "general bindings and alpha equivalence in nominal isabelle"
    - "coinductive big step operational semantics"
    - "the bedwyr system for model checking over syntactic expressions"
    - "higher order pattern complement and the strict λ calculus"

Connected through hyperedge HE-4 (induced by source paper "nominal unification of higher order expressions with recursive let"):
  with members:
    - "graph isomorphism in quasipolynomial time"
    - "nominal unification from a higher order perspective"
    - "general bindings and alpha equivalence in nominal isabelle"

Connected through hyperedge HE-5 (induced by source paper "reasoning about higher order relational specifications"):
  with members:
    - "a meta programming approach to realizing dependently typed logic programming"
    - "a framework for specifying prototyping and reasoning about computational systems"
    - "a two level logic approach to reasoning about computations"
    - "the abella interactive theorem prover system description"
    - "reasoning with higher order abstract syntax in a logical framework"

Connected through hyperedge HE-6 (induced by source paper "a simple sequent calculus for nominal logic"):
  with members:
    - "a dependent nominal type theory"

Connected through hyperedge HE-7 (induced by source paper "pnl to hol from the logic of nominal sets to the logic of higher order functions"):
  with members:
    - "nominal unification from a higher order perspective"

Connected through hyperedge HE-8 (induced by source paper "constraint solving in non permutative nominal abstract syntax"):
  with members:
    - "nominal unification from a higher order perspective"
    - "heap reference analysis using access graphs"

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.PL(Programming Languages)