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: "simplicity a new language for blockchains"
  Abstract: Simplicity is a typed, combinator-based, functional language without loops and recursion, designed to be used for crypto-currencies and blockchain applications. It aims to improve upon existing crypto-currency languages, such as Bitcoin Script and Ethereum's EVM, while avoiding some of the problems they face. Simplicity comes with formal denotational semantics defined in Coq, a popular, general purpose software proof assistant. Simplicity also includes operational semantics that are defined with an abstract machine that we call the Bit Machine. The Bit Machine is used as a tool for measuring the computational space and time resources needed to evaluate Simplicity programs. Owing to its Turing incompleteness, Simplicity is amenable to static analysis that can be used to derive upper bounds on the computational resources needed, prior to execution. While Turing incomplete, Simplicity can express any finitary function, which we believe is enough to build useful ``smart contracts'' for blockchain applications.

Connected through hyperedge HE-1 (induced by source paper "smart contract development from the perspective of developers topics and issues discussed on social media"):
  with members:
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "when energy trading meets blockchain in electrical power system the state of the art"
    - "slither a static analysis framework for smart contracts"
    - "what are the actual flaws in important smart contracts and how can we find them"
    - "verisolid correct by design smart contracts for ethereum"
    - "manticore a user friendly symbolic execution framework for binaries and smart contracts"
    - "tool demonstration fsolidm for designing secure ethereum smart contracts"
    - "finding the greedy prodigal and suicidal contracts at scale"

Connected through hyperedge HE-2 (induced by source paper "the security reference architecture for blockchains towards a standardized model for studying vulnerabilities threats and defenses"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "security and privacy on blockchain"
    - "deconstructing blockchains a comprehensive survey on consensus membership and structure"
    - "truffle tests for free replaying ethereum smart contracts for transparency"
    - "blockchain technologies for the internet of things research issues and challenges"
    - "exploring the attack surface of blockchain a systematic overview"
    - "strongchain transparent and collaborative proof of work consensus"

Connected through hyperedge HE-3 (induced by source paper "a survey on ethereum systems security vulnerabilities attacks and defenses"):
  with members:
    - "security and privacy on blockchain"
    - "exploring the attack surface of blockchain a systematic overview"
    - "a survey on consensus mechanisms and mining strategy management in blockchain networks"
    - "metrics towards measuring cyber agility"
    - "selfish mining in ethereum"
    - "a survey of distributed consensus protocols for blockchain networks"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"

Connected through hyperedge HE-4 (induced by source paper "smart contract development in practice trends issues and discussions on stack overflow"):
  with members:
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "when energy trading meets blockchain in electrical power system the state of the art"
    - "slither a static analysis framework for smart contracts"
    - "transax a blockchain based decentralized forward trading energy exchange for transactive microgrids"
    - "what are the actual flaws in important smart contracts and how can we find them"
    - "verisolid correct by design smart contracts for ethereum"
    - "manticore a user friendly symbolic execution framework for binaries and smart contracts"
    - "tool demonstration fsolidm for designing secure ethereum smart contracts"

Connected through hyperedge HE-5 (induced by source paper "verisolid correct by design smart contracts for ethereum"):
  with members:
    - "tool demonstration fsolidm for designing secure ethereum smart contracts"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"
    - "empirical vulnerability analysis of automated smart contracts security testing on blockchains"
    - "a semantic framework for the security analysis of ethereum smart contracts"
    - "lolisa formal syntax and semantics for a subset of the solidity programming language"
    - "vandal a scalable security analysis framework for smart contracts"
    - "securify practical security analysis of smart contracts"

Connected through hyperedge HE-6 (induced by source paper "a hybrid formal verification system in coq for ensuring the reliability and security of ethereum based service smart contracts"):
  with members:
    - "formal process virtual machine for smart contracts verification"
    - "scilla a smart contract intermediate level language"
    - "a semantic framework for the security analysis of ethereum smart contracts"
    - "fether an extensible definitional interpreter for smart contract verifications in coq"
    - "lolisa formal syntax and semantics for a subset of the solidity programming language"
    - "a general formal memory framework in coq for verifying the properties of programs based on higher order logic theorem proving with increased automation consistency and reusability"
    - "a survey of symbolic execution techniques"

Connected through hyperedge HE-7 (induced by source paper "concert a smart contract certification framework in coq"):
  with members:
    - "mi cho coq a framework for certifying tezos smart contracts"
    - "a certifying extraction with time bounds from coq to call by value lambda calculus"
    - "scilla a smart contract intermediate level language"
    - "total haskell is reasonable coq"
    - "revisiting parametricity inductives and uniformity of propositions"
    - "a concurrent perspective on smart contracts"

Connected through hyperedge HE-8 (induced by source paper "developing secure bitcoin contracts with bitml"):
  with members:
    - "scilla a smart contract intermediate level language"
    - "a semantic framework for the security analysis of ethereum smart contracts"
    - "securify practical security analysis of smart contracts"
    - "zero collateral lotteries in bitcoin and ethereum"
    - "modeling bitcoin contracts by timed automata"

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)