The phrase "able to prove how" is correct and usable in written English.
It can be used when discussing the capability to demonstrate a method or process of proving something.
Example: "The scientist was able to prove how the new theory applied to the existing data."
Alternatives: "capable of demonstrating how" or "able to show how".
Its coglike joints were first described in the 1950s, but it was only with advanced high-speed video that the scientists were able to prove how the joints worked.
I have had continuing support from my management in this effort, because I've been able to prove how much more I can accomplish by answering a question, and posting it on a blog, for example, than I can by answering the same question over and over.
There are still some gaps to fill here, since we were not able to prove how scores of mixed tuples (tuples containing some innocent and some guilty users) behave and whether their scores also stay below η with high probability.
For those unfamiliar, Smarterer wants you to be able to prove how proficient you are at using Salesforce, or Twitter, or Google Apps, all through a series of quizzes.
At least then we wouldn't be able to prove how dumb his statements are.
The judge had to go and get my Social Security records, and we were finally able to prove how much time I'd put in down there in the mines.
While the publication of Santorum's words was intended to prove how fearful the West is of ISIS, the 2012 presidential candidate was somehow able to find a silver lining.
Especially with the low-income consumers, you have no information on their creditworthiness and a lot of them work in the informal economy, so they wouldnt even be able to prove to you how much income they receive, says Jorge Gonzalez, professor of economics and dean of Occidental College in Los Angeles.
Joyce is able to prove that, given some conditions on how to measure distance or inaccuracy, a degree of belief function obeys the probability calculus if and only if there exists no alternative degree of belief function that is more accurate in each possible world (the only-if-part is not explicitly mentioned in Joyce 1998, but needed for the argument to work and present in Joyce 2009).
