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by wsxcde
2181 days ago
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Godel's incompleteness is not that complicated. The main insight Godel had was that proofs as well as provable statements can be encoded in numbers. This is obvious to everyone reading HN -- all computing works by encoding things into numbers. And it's easy to see how you'd encode proofs, proof rules etc. into numbers. (hint: as flattened ASTs!) The thing is, Godel didn't live in an era of pervasive computing so he came up with a wonky encoding based on products of powers of primes. This makes the proof technically challenging, but the fundamental idea is not that complex. What he was able to eventually do was encode a recursive statement of the form "this statement is not provable" where the "this" is kind of like a pointer back to the full statement. The rest is straightforward. |
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* axiomatizable extension of Q
* consistent
* complete
(where Q is a minimalistic arithmetical theory that can do addition and multiplication: https://en.wikipedia.org/wiki/Robinson_arithmetic)
It's true that the "main idea" of the proof is "everything is a natural number", which is obvious to us programmers (it possibly wasn't obvious to anyone in Godel's time). However, this is by no means the only trick that's used in the proof.