Now that A is even-times even is manifest;
for it has not its half odd. [VII. Def. 8]
I say next that it is also even-times odd.
For, if we bisect A, then bisect its half, and do this continually, we shall come upon some odd number which will measure A according to an even number.
For, if not, we shall come upon a dyad, and A will be among those which are doubled from a dyad: which is contrary to the hypothesis.
Thus A is even-times odd.
But it was also proved even-times even.
Therefore A is both even-times even and even-times odd.
Q. E. D.
Complete text
Book I