ELI5: Explain Like I'm 5

Hilbert–Bernays provability conditions

Hilbert-Bernays provability conditions are basically rules that help us make sure that the things we say are provable or can be proven. Let's say you're playing a game where you have to prove that something is true. You can't just say something is true without proving it, right? So how do you know that what you're saying is really true and can be proven?

Well, that's where these provability conditions come in. They give us certain rules that we have to follow in order to make sure that what we're saying is really provable. These rules help us avoid making mistakes or saying things that aren't really true.

Think of it like building a tower out of blocks. You have to put the blocks in the right order and make sure they're stable, or else the tower might fall down. Similarly, when we're proving something, we have to follow certain rules to make sure that our "tower" of proof is stable and won't fall down.

Some of these rules include things like making sure that our definitions are clear and consistent, making sure that we're not using circular reasoning (where we assume the thing we're trying to prove), and making sure that we're following certain logical steps to get to our conclusion.

So why do we need these provability conditions? Well, if we didn't have them, we might make mistakes and say things that aren't really true. We might also waste a lot of time trying to prove things that can't be proven because we're not following the right rules.

But with these provability conditions, we can be more confident that what we're saying is really true and can be proven. So next time you're playing a game where you have to prove something, remember to follow the Hilbert-Bernays provability conditions to make sure your tower of proof is stable and strong!