Hehe.. well nothing is truly provable anyway, and it's only provable within the confines of that particular structure or belief system to use as a reference point or foundation. Without that, it's just floating words

. Any system/method of 'provability' has inherent within it the limitation of its own basis. Once you question the basis, it leaves not much to say, much less prove!
We can use logic, evidence of repeatability/consistency (the scientific method), just anecdotal experience, or other means for the time being for entertainment. (But I sense a slippery slope emerging for the future of this thread... can't prove it though XD )