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: "lolisa formal syntax and semantics for a subset of the solidity programming language"
  Abstract: This article presents the formal syntax and semantics for a large subset of the Solidity programming language developed for the Etheruem blockchain platform based on our resent work about developing a general, extensible, and reusable formal memory (GERM) framework and an extension of Curry-Howard isomorphism, denoted as execution-verification isomorphism (EVI). This subset is denoted as Lolisa, which, to our knowledge, is the first mechanized and validated formal syntax and semantics developed for Solidity. The formal syntax of Lolisa adopts a stronger static type system than Solidity for enhanced type safety. In addition, Lolisa not only includes nearly all the syntax components of Solidity, such as mapping, modifier, contract, and address types, but it also contains general-purpose programming language features, such as multiple return values, pointer arithmetic, struct, and field access. Therefore, the inherent compatibility of Lolisa allows Solidity programs to be directly translated into Lolisa with a line-by-line correspondence without rebuilding or abstracting, and, in addition, the inherent generality of Lolisa allows it to be extended to express other programming languages as well. To this end, we also present a preliminary scheme for extending Lolisa to other languages systematically.

Connected through hyperedge HE-1 (induced by source paper "security analysis methods on ethereum smart contract vulnerabilities a survey"):
  with members:
    - "easyflow keep ethereum away from overflow"
    - "a security case study for blockchain games"
    - "a hybrid formal verification system in coq for ensuring the reliability and security of ethereum based service smart contracts"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"
    - "formal process virtual machine for smart contracts verification"
    - "scilla a smart contract intermediate level language"
    - "empirical vulnerability analysis of automated smart contracts security testing on blockchains"

Connected through hyperedge HE-2 (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"
    - "vandal a scalable security analysis framework for smart contracts"
    - "securify practical security analysis of smart contracts"
    - "executable operational semantics of solidity"

Connected through hyperedge HE-3 (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"
    - "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"
    - "simplicity a new language for blockchains"
    - "a survey of symbolic execution techniques"

Connected through hyperedge HE-4 (induced by source paper "a minimal core calculus for solidity contracts"):
  with members:
    - "verisolid correct by design smart contracts for ethereum"
    - "caterpillar a business process execution engine on the ethereum blockchain"
    - "scilla a smart contract intermediate level language"
    - "executable operational semantics of solidity"
    - "a concurrent perspective on smart contracts"

Connected through hyperedge HE-5 (induced by source paper "fether an extensible definitional interpreter for smart contract verifications in coq"):
  with members:
    - "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"
    - "simplicity a new language for blockchains"
    - "a survey of symbolic execution techniques"
    - "mechanized semantics for the clight subset of the c language"

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)