Smart contracts are currently en vogue, thanks to the infrastructure provided by the blockchain technology. However, their effective use requires that the textual (legalese) specification of the contract be accompanied by a precise computational definition of the actions leading to its satisfaction or breach, as well as of their admissible sequences. Insofar as contracts can be viewed as prescribing transactional exchanges of well-specified resources among well-specified actors, contract execution can be modelled as following some protocol in a closed world. This suggests a modeling of such executions as interactive processes in reaction systems, where the entities in the background set represent possible allocations of resources to actors and reactions describe changes in such allocations. We use this type of reaction systems and interactive processes as a basis for the modelling of transactions and contracts and explore properties of such processes, highlighting their peculiarities with respect to the original notion of interactive processes in reaction systems. We also discuss several constructions for composition and decomposition of processes, which guarantee equivalence of effects: two interactive processes are equivalent if, starting from the same initial set of allocations, they produce the same final set of allocations.

智能合约目前很流行，感谢区块链技术提供的基础设施。然而，它们的有效使用要求合同的文本（法律）规范伴随着导致其满足或违约的行为的精确计算定义，以及它们的可接受序列。就合同可以被视为规定明确指定的参与者之间明确指定资源的交易交换而言，合同执行可以被建模为遵循封闭世界中的某些协议。这建议将此类执行建模为反应系统中的交互过程，其中背景集中的实体代表可能的资源分配给参与者，反应描述此类分配的变化。我们使用这种类型的反应系统和交互过程作为交易和合同建模的基础，并探索这些过程的特性，突出它们相对于反应系统中交互过程的原始概念的特殊性。我们还讨论了用于过程组合和分解的几种结构，它们保证了效果的等效性：如果两个交互过程从相同的初始分配集开始，它们产生相同的最终分配集，则它们是等效的。