Comment by thatguysaguy

I believe it is rooted in legal proceedings where you are usually not required to in principle because it can be hard and/or impossible.

Eg. it is extremely hard to prove you "weren't there" (eg. at a crime site) if you cannot easily prove you were somewhere else (an affirmative): we do not keep court-admissible record of our whereabouts in case we get suspected of being in a place we were not in.

So it does hold in a number of cases where keeping evidence is required for proof. In software, that evidence would be formal specs and test reports which prove that cases covered with those are indeed working as specced, but provide no proof outside those "specs" (loosely considering an automated test a spec too).

It's pretty easy to prove lots of negatives outside of mathematics, too. It's easy to prove there's no elephant in my living room at the moment.

Also, what even is "a negative"? The following statements are equivalent:

"There are no squares with diagonals of different lengths"

"All squares have diagonals of equal lengths"

Similarly, I can rephrase the statement about the absence of bugs. These are equivalent:

"This program has no bugs"

"This program always does exactly what it is supposed to do"

If you think you can't prove the first statement, then go ahead and prove the second one.

Are people thinking of falsification when talking about "proving negatives"? I.e. you can only falsify statements about the physical world, never prove them.