For a continuous map of tree or graph to itself, we show the properties that every isolated chain recurrent point is an eventually periodic point, and an isolated chain recurrent point which is not in the orbit of a critical point and has no critical point in its orbit is a periodic point.
对树或图上的连续自映射，本文证明了孤立链回归点是最终周期点，如孤立链回归点不在临界点的轨道中且它的轨道中也不含有临界点，则它还是周期点。