In figure 13 , which shows a composition relationship between a company class and a department class , notice that the composition relationship is drawn like the aggregation relationship , but this time the diamond shape is filled 在图13中，显示了company类和department类之间的组合关系，注意组合关系如聚合关系一样绘制，不过这次菱形是被填充的。
After analysis of inherit , logical and aggregation relationships among the objects , the object sets of problem domain , system data structure and application frameworks were designed , and the system extensibility was also discussed 通过对象之间继承关系、逻辑关系和聚合关系的分析，设计了领域问题对象集、系统数据结构和应用框架，并讨论了系统的可扩充性。
