rood sum graph的用法和樣例：
例句
- It is the combination of probability and graph theory, and can be used in analyzing complicated multi-causality questions.
它是概率論和圖論相結合的產物，可用於複雜多因果關係的分析，是人工智慧領域的研究熱點和重要成果之一。 - A description was carried out on the complicated epicyclic gear train by adopting the functional schematic diagram and the knowledge of graph theory.
摘要採用功能示意圖和圖論知識對複雜周轉輪系進行描述。
