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On 2025-06-12 09:44:06 +0000, WM said:It is part of the proof because it specifies the set which the proof is based upon.
On 12.06.2025 10:00, Mikko wrote:That is a part of the sentence that mentions the proof, not a part ofOn 2025-06-11 11:38:52 +0000, WM said:>>Outside of ZF in correct mathematics this proof for all definable numbers n>
|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.
It does not show that. The "proof" does not even mention definability.
"this proof for all definable numbers n"
the proof itself.
It is always concerning individuals only.∀n ∈ ℕ: P(n) specifies that every natural number n as an individual has the property P.Quantification is never "as individuals".The conclusion follows from the second sentence alone when n is understood>
to be universally quantified, so the first sentence is not needed and should
not be there.
It is there. Only definablenumbers can be quantified as individuals.
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