But he's going to prove his theory or die trying.

But just then, he had no further opportunity for proving his theory.

She looked around the room for something to prove her theories.

"Would you like to touch it and prove your theory?"

He discovered in a dream how to prove his theory.

Proving his theory would require that he break the law.

"It goes to prove my old theory that we probably had a few more decades left," he said.

I'm sorry that he didn't conduct any research to prove his theory!

But I had proved my theory and the heart of the scam.

So far he had been only partially successful in proving his theory.