更改

We can also define the number of triangles that vertex <math>i</math> is involved in as <math>\delta (i)</math> and, as each triangle is counted three times, we can express the number of triangles in G as <math>\delta (G) = \frac{1}{3} \sum_{i\in V} \ \delta (i)</math>.  

We can also define the number of triangles that vertex <math>i</math> is involved in as <math>\delta (i)</math> and, as each triangle is counted three times, we can express the number of triangles in G as <math>\delta (G) = \frac{1}{3} \sum_{i\in V} \ \delta (i)</math>.  

我们也可以将顶点<math>i</math>所涉及的三角形的数量定义为<math>\delta（i）</math>，并且，由于每个三角形都被计数了三次，因此我们可以表示 G中的三角形为<math>\delta（G）= \frac{1}{3} \sum_{i\in V} \ \ delta（i）</math>。

我们也可以将顶点<math>i</math>所涉及的三角形的数量定义为<math>\delta（i）</math>，并且，由于每个三角形都被计数了三次，因此我们可以表示 G中的三角形为<math>\delta (G) = \frac{1}{3} \sum_{i\in V} \ \delta (i)</math>。