On: I am often asked if I will “return to cryptocurren...

[randomswede]

If facts are time-constrained, then a statement that was at one point factual may stop being factual. I would still consider that to be an existence proof that "facts change".

You may want to put some temporal logic spin on it, if that makes you happier (technically, it makes me happier, but I am content with saying "facts can change"), but the question I was trying to answer was "do facts change". I think I demonstrated that what once was factual may stop being factual.

[ric2b → randomswede]

Not really. "As of 1981, there is a country in Europe named Yugoslavia" is a fact that never stops being factual.

At least this is the view that many functional programmers like to use and I find it useful.

In that model, a statement that can vary in time isn't a fact.

[randomswede → ric2b]

That is a statement that requires you to reason within a temporal logic. And it is a statement that is not equivalent to "There is a country in Europe named Yugoslavia".