Secondly, domino model, pyramid model, reverse pyramid model, and cellular automaton model have been presented in order to explain the concepts of brittleness clearly.

• 其次，为了形象化说明复杂系统脆性的概念，提出了多米诺骨牌模型、金字塔与倒金字塔模型、元胞自动机模型等几种基本模型。