Of course, there was nothing left to prove by that time.
It was as though he wanted to prove something by this.
But you couldn't prove it by me, or my family.
Eventually, something comes out that seems to be a book, but you can't prove it by me.
It's probably for the better, but you couldn't prove it by this group.
He seems to be making progress, but you cannot prove that by him.
That may end up being its strength, although you will never prove it by me.
They will have to prove by the criteria above that the person is in fact dead.
What they mean is that you can prove anything by bad logic.
In fact, the idea may prove too clever by half.