"proven capable of" is correct and usable in written English.
It is typically used to indicate that something has been demonstrated to have the ability to do something. For example, "The student was proven capable of completing the assignment with aplomb."
The Kurds have proven capable of establishing common cause with Arab tribes.
Lewis went on: "Conservatives should be worried that Walker hasn't proven capable of navigating these land mines".
"From the streets of Iraqi cities to rural villages in Afghanistan, time and again women have proven capable of serving honorably and bravely.
If so, it is misguided; just after Drum is proven capable of fatherhood, Charlie again refers to his dog as "girl".
Syria's ongoing civil war has unexpectedly given rise to one of the most high-profile hacking groups to date, proven capable of influencing global politics.
He has consistently proven capable of getting production from the quarterback, whether it be Donovan McNabb, Michael Vick or to lesser extents Kevin Kolb and Nick Foles.
The 6-3 Sue Wicks, who had what many said was her best pro season last year, has proven capable of shooting from the perimeter, posting up and playing defense.
He has already proven capable of rising to the big occasion, having scored his first senior goal on his Champions League debut in the knockout stages against Real Madrid earlier this year.
What makes the 49ers offense so dangerous, is that even if the Ravens successfully stop the run, Kaepernick has proven capable of connecting with his receivers consistently from the pocket.
What Europe has proven capable of doing for its future graduates, it can and must do again today for its less qualified young people – inevitably the ones worst hit by unemployment.
Kerr and the Warriors assistant coach Alvin Gentry brought D'Antoni's system with them to the Bay Area nonetheless, and that is where it has proven capable of a crowning coup d'état.
