Abstract: It is given a geometrical proof of an essential combinatorial lemma of Liao.

Key words: stability problem, shadowing lemma, λ-quasi-hyperbolic sequence

摘要： 给出廖山涛一个关键的组合引理一个几何式的证明。

关键词: 稳定性问题, 伪轨跟踪引理, 拟双曲序列