The fact that C++ is Turing complete does not prevent it from computing that 1+1=2. Similarly, the fact that C++ is Turing complete does not prevent programs created from it from verifying the proofs that they have verified. The proof of the halting problem (and incompleteness proofs based on the halting problem) itself halts. https://leanprover-community.github.io/mathlib_docs/computability/halting.html
It’s not about those specific proofs. You’re claiming, that every possible proof stated in lean will always halt. Lean tries to evade the halting problem best as possible, by requiring functions to terminate before it runs a proof. But it’s not able to determine for every lean program it halts or not. That would solve the halting problem. Furthermore, the kernel still relies on CPU, memory and OS behavior to be bug free. Can you be sure enough in practice, yeah probably. But you’re claiming absolute metaphysical certainty that abolishes the need for philosophy and sorry, but no software will ever achieve that.
It is not necessary to solve the halting problem to show that a particular lean proof is correct.
Lean runs on C++. C++ is a turning complete, compiled language. It and it’s compiler are subject to the halting problem.
The fact that C++ is Turing complete does not prevent it from computing that 1+1=2. Similarly, the fact that C++ is Turing complete does not prevent programs created from it from verifying the proofs that they have verified. The proof of the halting problem (and incompleteness proofs based on the halting problem) itself halts. https://leanprover-community.github.io/mathlib_docs/computability/halting.html
It’s not about those specific proofs. You’re claiming, that every possible proof stated in lean will always halt. Lean tries to evade the halting problem best as possible, by requiring functions to terminate before it runs a proof. But it’s not able to determine for every lean program it halts or not. That would solve the halting problem. Furthermore, the kernel still relies on CPU, memory and OS behavior to be bug free. Can you be sure enough in practice, yeah probably. But you’re claiming absolute metaphysical certainty that abolishes the need for philosophy and sorry, but no software will ever achieve that.