In order to obtain the answers, the applications to study the containment relations between classes of greedoids are discussed by constructing a poset for all greedoids defined on the same set.

• 为得到答案，首先对于定义在同一集上的全体广义拟阵构造一个偏序关系，运用这种偏序关系讨论不同种的广义拟阵间的包含关系。