To establish by evidence.
To test.
To learn by experience.
To turn out, or be found to be.
I am about to prove it. – An Amiable Charlatan by E. Phillips Oppenheim
Who is to prove it? – East Lynne by Mrs. Henry Wood
We shall prove beyond a doubt, that the Begums had nothing to do with it. – The Works of the Right Honourable Edmund Burke, Vol. XII. (of XII.) by Edmund Burke