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On 12/17/2024 5:12 PM, WM wrote:
There are no definable cardinals common to all endsegments of definable cardinals. Finite cardinals are in all non-empty endsegments.We have the sequence ofHere is a counter.example to your claimed requirement:
intersections of endsegments
f(k) = ∩{E(1), E(2), ..., E(k)}
with E(1) = ℕ
and the definition of that function
∀k ∈ ℕ :
∩{E(1), E(2), ..., E(k+1)} =
∩{E(1), E(2), ..., E(k)} \ {k}
and the fact that
∩{E(1), E(2), ...} is empty.
More is not required to prove
the existence of finite endsegments.
There are no finite.cardinals common to
all the infinite end.segments of finite.cardinals.
The infinite end.segments of finite.cardinalsExplicitly wrong. As long as only infinite endsegments are concerned their intersection is infinite.
do not include any finite end.segments and
they have an empty intersection.
----There are no limits involved. Cantor uses "all natural numbers" (no limit) in his bijections, that means to use them all coming out of endsegments. None remains. The intersection of all endegments is empty. But it gets empty one by one.
More generally,
for limit.set Lim.⟨A₀,A₁,A₂,…⟩ of
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