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: "higher order approximate relational refinement types for mechanism design and differential privacy"
  Abstract: Mechanism design is the study of algorithm design where the inputs to the algorithm are controlled by strategic agents, who must be incentivized to faithfully report them. Unlike typical programmatic properties, it is not sufficient for algorithms to merely satisfy the property, incentive properties are only useful if the strategic agents also believe this fact.   Verification is an attractive way to convince agents that the incentive properties actually hold, but mechanism design poses several unique challenges: interesting properties can be sophisticated relational properties of probabilistic computations involving expected values, and mechanisms may rely on other probabilistic properties, like differential privacy, to achieve their goals.   We introduce a relational refinement type system, called HOARe2, for verifying mechanism design and differential privacy. We show that HOARe2 is sound w.r.t. a denotational semantics, and correctly models (epsilon,delta)-differential privacy; moreover, we show that it subsumes DFuzz, an existing linear dependent type system for differential privacy. Finally, we develop an SMT-based implementation of HOARe2 and use it to verify challenging examples of mechanism design, including auctions and aggregative games, and new proposed examples from differential privacy.

Connected through hyperedge HE-1 (induced by source paper "guidelines for implementing and auditing differentially private systems"):
  with members:
    - "differentially private objective perturbation beyond smoothness and convexity"
    - "identifying cache based side channels through secret augmented abstract interpretation"
    - "fuzzi a three level logic for differential privacy"
    - "an economic analysis of privacy protection and statistical accuracy as social choices"
    - "private selection from private candidates"
    - "ektelo a framework for defining differentially private computations"
    - "detecting violations of differential privacy"
    - "how to use heuristics for differential privacy"

Connected through hyperedge HE-2 (induced by source paper "duet an expressive higher order language and linear type system for statically enforcing differential privacy"):
  with members:
    - "fuzzi a three level logic for differential privacy"
    - "approximate span liftings compositional semantics for relaxations of differential privacy"
    - "bidirectional type checking for relational properties"
    - "probabilistic relational reasoning via metrics"
    - "subsampled r enyi differential privacy and analytical moments accountant"
    - "renyi differential privacy"
    - "a semantic account of metric preservation"
    - "towards practical differential privacy for sql queries"

Connected through hyperedge HE-3 (induced by source paper "a programming framework for differential privacy with accuracy concentration bounds"):
  with members:
    - "fuzzi a three level logic for differential privacy"
    - "proving differential privacy with shadow execution"
    - "ektelo a framework for defining differentially private computations"
    - "synthesizing coupling proofs of differential privacy"
    - "apex accuracy aware differentially private data exploration"
    - "renyi differential privacy"
    - "lightdp towards automating differential privacy proofs"
    - "advanced probabilistic couplings for differential privacy"

Connected through hyperedge HE-4 (induced by source paper "proving differential privacy with shadow execution"):
  with members:
    - "property testing for differential privacy"
    - "ektelo a framework for defining differentially private computations"
    - "detecting violations of differential privacy"
    - "synthesizing coupling proofs of differential privacy"
    - "relational symbolic execution"
    - "renyi differential privacy"
    - "towards practical differential privacy for sql queries"
    - "lightdp towards automating differential privacy proofs"

Connected through hyperedge HE-5 (induced by source paper "the complexity of verifying loop free programs as differentially private"):
  with members:
    - "automated methods for checking differential privacy"
    - "property testing for differential privacy"
    - "bisimilarity distances for approximate differential privacy"
    - "detecting violations of differential privacy"
    - "synthesizing coupling proofs of differential privacy"
    - "lightdp towards automating differential privacy proofs"
    - "understanding the sparse vector technique for differential privacy"
    - "proving differential privacy via probabilistic couplings"

Connected through hyperedge HE-6 (induced by source paper "approximate span liftings compositional semantics for relaxations of differential privacy"):
  with members:
    - "synthesizing coupling proofs of differential privacy"
    - "renyi differential privacy"
    - "liftings for differential privacy"
    - "lightdp towards automating differential privacy proofs"
    - "advanced probabilistic couplings for differential privacy"
    - "concentrated differential privacy simplifications extensions and lower bounds"
    - "approximate relational hoare logic for continuous random samplings"
    - "differentially private bayesian programming"

Connected through hyperedge HE-7 (induced by source paper "relational reasoning for markov chains in a probabilistic guarded lambda calculus"):
  with members:
    - "proving uniformity and independence by self composition and coupling"
    - "the guarded lambda calculus programming and reasoning with guarded recursion for coinductive types"
    - "coupling proofs are probabilistic product programs"
    - "a relational logic for higher order programs"
    - "guarded dependent type theory with coinductive types"
    - "differentially private bayesian programming"
    - "relational reasoning via probabilistic coupling"
    - "a lambda calculus foundation for universal probabilistic programming"

Connected through hyperedge HE-8 (induced by source paper "probabilistic relational reasoning via metrics"):
  with members:
    - "duet an expressive higher order language and linear type system for statically enforcing differential privacy"
    - "approximate span liftings compositional semantics for relaxations of differential privacy"
    - "a domain theory for statistical probabilistic programming"
    - "proving expected sensitivity of probabilistic programs"
    - "a semantic account of metric preservation"
    - "approximate relational hoare logic for continuous random samplings"
    - "differentially private bayesian programming"
    - "monads need not be endofunctors"

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)