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On 2025-06-11 11:38:52 +0000, WM said:
"this proof for all definable numbers n"Outside of ZF in correct mathematics this proof for all definable numbers nIt does not show that. The "proof" does not even mention definability.
|ℕ \ {1}| = ℵo.
|ℕ \ {m ∈ ℕ | m < n}| = ℵo
==> |ℕ \ {m ∈ ℕ | m < n+1}| = ℵo.
shows that is impossible to extend definability to all natural numbers with none remaining undefined.
The conclusion follows from the second sentence alone when n is understoodIt is there. Only definablenumbers can be quantified as individuals.
to be universally quantified, so the first sentence is not needed and should
not be there.
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