Cycloids are particular Petri nets for modelling processes of actions and events, belonging to the fundaments of Petri's general systems theory. Defined by four parameters they provide an algebraic formalism to describe strongly synchronized sequential processes. To further investigate their structure, reduction systems of cycloids are defined in the style of rewriting systems and properties of irreducible cycloids are proved. In particular the synthesis of cycloid parameters from their Petri net structure is derived, leading to an efficient method for a decision procedure for cycloid isomorphism.

翻译：环形是一类特殊的Petri网，用于建模动作与事件的过程，属于Petri一般系统理论的基础。通过四个参数定义，它们提供了一种代数形式化方法来描述强同步的顺序过程。为深入研究其结构，本文以重写系统的风格定义了环形的归约系统，并证明了不可约环形的性质。特别地，本文推导了从Petri网结构合成环形参数的方法，从而为环形同构判定问题提供了一种高效的决策过程。