一句话：用 proarrow equipment 的字符串图刻画并发过程产生的物质历史，并构造资源转换器范畴。
本文研究并发过程所生成的物质历史具有何种代数结构。作者将已有的资源可转换性范畴理论推广到并发交互场景，从而为并发资源的转换与组合建立统一的形式框架。该形式化可用 proarrow equipment 的字符串图直观呈现，使并发过程之间的交互与资源流动获得图形化表达。论文还考察了由该结构诱导出的若干资源转换器范畴，指出这些范畴具有不寻常的结构，因而本身也值得研究。整体贡献在于连接并发过程、资源可转换性与范畴论及字符串图方法。
We identify the algebraic structure of the material histories generated by concurrent processes. Specifically, we extend existing categorical theories of resource convertibility to capture concurrent interaction. Our formalism admits an intuitive graphical presentation via string diagrams for proarrow equipments. We also consider certain induced categories of resource transducers, which are of independent interest due to their unusual structure.