disjoint sets meaning in English

不交集
不相交集

To improve the execution performance of wcsg model , all transformation productions , which express executable semantics of wscg model , have been divided into several parallel independent disjoint set , and sequential independent sets for every transformation productions are also defined
论文也通过构造变换产生式集合的并行不相关割集和变换产生式的顺序不相关集合，设计了wscg模型的执行算法，改善执行效率。