Commentary on Proposition VII.23

Back to Proposition VII.23.

[Folio 0331 | p. 325]

If $a$, $mb$ are prime to one another, $b$ is prime to $a$. For, if not, some number $d$ will measure both $a$ and $b$, and therefore both $a$ and $mb$: which is contrary to the hypothesis.

Therefore etc.