I sorry, but I am truly confused at the logic here.
If X, then Y.
To test X works you first you start on Y?
If Y succeeds then you don't know if X failed or not && if Y fails then you know that X failed too?
If X, then Y.
To test X works you first you start on Y?
If Y succeeds then you don't know if X failed or not && if Y fails then you know that X failed too?
In the case of a an X that is hard to figure out on its own, and it is easy to figure out Y, then it might be worth testing Y first, even if you will only get useful information if Y is false.
If you don't find the coat in your closet, you will don't know whether you left it at work. It could be in your car or maybe you left it on the train. But it's still worth checking your closet first because that gives you an early possible solution.
In logic, that's: If coat is at work, then closet is empty.
X = "Coat is at work".
Y = "Closet is empty".
Modus tollens tells us that "If X, then Y" implies "If not Y, then not X." So: If closet is not empty, then coat is not at work.
Using the same logic as the parent comment, I would be very suspicious of the general applicability of this algorithm. Because, if this algorithm was correct, P would be equal to NP based off of this algorithm, because you'd have a polynomial solution to SAT. This, in turn, would invalidate pretty much all practical cryptography, most likely turn bitcoin on its head, and cause a significant number of other disruptions.
That is this line of thinking. The formal name is Modus Tollens, but it basically says: If your assumption is right, I can propose a much more preposterous assumption that would also be right. Or I could propose something enabled or validated by your assumption which is much easier to invalidate.
I constantly use this in stupid security discussions as well. There are so many people asking about silly threat scenarios, but the specific threat scenarios generally imply that an attacker already has control of critical infrastructure anyway, and all of these nitpicky things they wonder about are just not relevant. Like, if you assume this action to be possible, they have control of the secret management solution, and then we are doomed already.