If two numbers measure any number, the least number measured by them will also measure the same.
如果两个数都量尽某个数,那么它们所量尽的最小数也能量尽该数。
本页以“两数公倍数整除性质”整体图解辅助阅读;点、线、角、圆索引已按命题文字和证明步骤校订,可与证明和问答联动。
正文图形由校订坐标生成;点、线、角、圆可与证明和问答联动。
For let the two numbers A, B measure any number CD, and let E be the least that they measure; I say that E also measures CD.
设两数A、B量尽某数CD,且E是它们量尽的最小数。
For, if E does not measure CD, let E, measuring DF, leave CF less than itself.
假设E不量尽CD,则让E量尽DF,余下CF小于E。
Now, since A, B measure E, and E measures DF, therefore A, B will also measure DF.
由于A、B量尽E,且E量尽DF,所以A、B也量尽DF。
But they also measure the whole CD; therefore they will also measure the remainder CF which is less than E: which is impossible.
但A、B也量尽整个CD,因此它们也量尽余数CF,而CF小于E,这是不可能的。