We implement two versions of a simple but illustrative smart contract: one in Solidity on the Ethereum blockchain platform, and one in Plutus on the Cardano platform, with annotated code excerpts and with source code attached. We get a clearer view of the Cardano programming model in particular by introducing a novel mathematical abstraction which we call Idealised EUTxO. For each version of the contract, we trace how the architectures of the underlying platforms and their mathematics affects the natural programming styles and natural classes of errors. We prove some simple but novel results about alpha-conversion and observational equivalence for Cardano, and explain why Ethereum does not have them. We conclude with a wide-ranging and detailed discussion in the light of the examples, mathematical model, and mathematical results so far.

中文翻译：

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UTxO- vs 基于账户的智能合约区块链编程范式

我们实现了一个简单但具有说明性的智能合约的两个版本：一个在以太坊区块链平台上的 Solidity 中，另一个在 Cardano 平台上的 Plutus 中，带有带注释的代码摘录和源代码。特别是通过引入一种我们称为理想化 EUTxO 的新颖数学抽象，我们可以更清楚地了解卡尔达诺编程模型。对于合约的每个版本，我们都会追踪底层平台的架构及其数学如何影响自然编程风格和自然错误类别。我们证明了一些关于 Cardano 的 alpha 转换和观察等效的简单但新颖的结果，并解释了为什么以太坊没有它们。我们根据迄今为止的例子、数学模型和数学结果进行了广泛而详细的讨论。