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: "refinement type inference via horn constraint optimization"
  Abstract: We propose a novel method for inferring refinement types of higher-order functional programs. The main advantage of the proposed method is that it can infer maximally preferred (i.e., Pareto optimal) refinement types with respect to a user-specified preference order. The flexible optimization of refinement types enabled by the proposed method paves the way for interesting applications, such as inferring most-general characterization of inputs for which a given program satisfies (or violates) a given safety (or termination) property. Our method reduces such a type optimization problem to a Horn constraint optimization problem by using a new refinement type system that can flexibly reason about non-determinism in programs. Our method then solves the constraint optimization problem by repeatedly improving a current solution until convergence via template-based invariant generation. We have implemented a prototype inference system based on our method, and obtained promising results in preliminary experiments.

Connected through hyperedge HE-1 (induced by source paper "coinduction in uniform foundations for corecursive proof search with horn clauses"):
  with members:
    - "coinductive uniform proofs"
    - "towards coinductive theory exploration in horn clause logic position paper"
    - "breaking the loop recursive proofs for coinductive predicates in fibrations"
    - "productive corecursion in logic programming"
    - "guarded dependent type theory with coinductive types"
    - "proof relevant corecursive resolution"
    - "sequent calculus in the topos of trees"
    - "first steps in synthetic guarded domain theory step indexing in the topos of trees"

Connected through hyperedge HE-2 (induced by source paper "coinductive uniform proofs"):
  with members:
    - "productive corecursion in logic programming"
    - "type theory based on dependent inductive and coinductive types"
    - "proof relevant corecursive resolution"
    - "combining deduction modulo and logics of fixed point definitions"
    - "inductive and coinductive components of corecursive functions in coq"

Connected through hyperedge HE-3 (induced by source paper "generalized property directed reachability for hybrid systems"):
  with members:
    - "sharper and simpler nonlinear interpolants for program verification"
    - "ic3 modulo theories via implicit predicate abstraction"
    - "smt based induction methods for timed systems"
    - "computing semi algebraic invariants for polynomial dynamical systems"

Connected through hyperedge HE-4 (induced by source paper "local refinement typing"):
  with members:
    - "refinement types for typescript"
    - "refinement reflection or how to turn your favorite language into a proof assistant using smt"
    - "program synthesis from polymorphic refinement types"
    - "occurrence typing modulo theories"
    - "smt based model checking for recursive programs"
    - "hmc verifying functional programs using abstract interpreters"
    - "software model checking via large block encoding"

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)