MY ERRATA , MY FRIEND : the most harmless math mistakes

           I like to look for mistakes in other people's works. So, I don't have time to find my own mistakes.

           I was reading a wonderful book yesterday: 

My Numbers, My Friends (Popular Lectures on Number Theory) by the author  Paulo Ribenboim.

A first mistake, more of a haste than a typo, appears on page 10 (see marked text).

In the marked place, the correct text is :

$$...\;if\;p\;is\;a\;prime\;dividing\;both\;P,\;Q,\;then...$$

$\blacksquare$

Those who wish can read as much as they want by clicking on the image of the book cover.