Therefore E and A are not relatively prime. Therefore they are relatively composite. But numbers relatively composite are measured by some number.
And, since E is by hypothesis prime, and a prime is not measured by any number other than itself, therefore E measures A and E, so that E measures A.
But it also measures D, therefore E measures A and D. Similarly we can prove that, by whatever prime numbers D is measured, A also is measured by the same.
Therefore, if as many numbers as we please beginning from a unit are in continued proportion, then by whatever prime numbers the last is measured, the next to the unit is also measured by the same.