human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "refinement types for ruby"):
  Abstract: Refinement types are a popular way to specify and reason about key program properties. In this paper, we introduce RTR, a new system that adds refinement types to Ruby. RTR is built on top of RDL, a Ruby type checker that provides basic type information for the verification process. RTR works by encoding its verification problems into Rosette, a solver-aided host language. RTR handles mixins through assume-guarantee reasoning and uses just-in-time verification for metaprogramming. We formalize RTR by showing a translation from a core, Ruby-like language with refinement types into Rosette. We apply RTR to check a range of functional correctness properties on six Ruby programs. We find that RTR can successfully verify key methods in these programs, taking only a few minutes to perform verification.

Includes members:
  Member "verified low level programming embedded in f":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "computer aided proofs for multiparty computation with active security")
  Member "a relational logic for higher order programs":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "operationally based program equivalence proofs using lctrss")
  Member "refinement types for typescript":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "type level computations for ruby libraries")
  Member "just in time static type checking for dynamic languages":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "type level computations for ruby libraries")
  Member "jsketch sketching for java":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "intriguing properties of adversarial ml attacks in the problem space")
  Member "occurrence typing modulo theories":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "type level computations for ruby libraries")
  Member "automated feedback generation for introductory programming assignments":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "grand challenges of resilience autonomous system resilience through design and runtime measures")

Question: Please tell me which class the source paper 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)