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: "from f to dot type soundness proofs with definitional interpreters"
  Abstract: Scala's type system unifies ML modules, object-oriented, and functional programming. The Dependent Object Types (DOT) family of calculi has been proposed as a new foundation for Scala and similar languages. Unfortunately, it is not clear how DOT relates to any well-known type systems, and type soundness has only been established for very restricted subsets. In fact, important Scala features are known to break at least one key metatheoretic property such as environment narrowing or subtyping transitivity, which are usually required for a type soundness proof. #R##N#First, and, perhaps surprisingly, we show how rich DOT calculi can still be proved sound. The key insight is that narrowing and subtyping transitivity only need to hold for runtime objects, but not for code that is never executed. Alas, the dominant method of proving type soundness, Wright and Felleisen's syntactic approach, is based on term rewriting, which does not a priori make a distinction between runtime and type assignment time. #R##N#Second, we demonstrate how type soundness can be proved for advanced, polymorphic, type systems with respect to high-level, definitional interpreters, implemented in Coq. We present the first mechanized soundness proof in this style for System F<: and several extensions, including mutable references. Our proofs use only simple induction: another surprising result, as the combination of big-step semantics, mutable references, and polymorphism is commonly believed to require co-inductive proof techniques. #R##N#Third, we show how DOT-like calculi emerge as generalizations of F<:, exposing a rich design space of calculi with path-dependent types which we collectively call System D. Armed with insights from the definitional interpreter semantics, we also show how equivalent small-step semantics and soundness proofs in Wright-Felleisen-style can be derived for these systems.

Connected through hyperedge HE-1 (induced by source paper "bonsai synthesis based reasoning for type systems"):
  with members:
    - "dynamic witnesses for static type errors or ill typed programs usually go wrong"
    - "dynamic witnesses for static type errors"
    - "higher order symbolic execution for contract verification and refutation"

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)