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Re: Matheology ?019
Posted:
Jun 4, 2012 2:37 PM
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On 4 Jun., 19:42, "dilettante" <n...@nonono.no> wrote:
> >The limit was exactly the same if all your intervals started at -1 or > >+1, respectively. The difference is that a truely connected component > >has its limit independent of the finite definition of a sequence: If > >there are intervals like [0, 1-1/n], then, independent of any > >definition, the first possibility for an uncovered point would be the > >0. > > Of course the limit is the same. There is no dispute about that. But the > connected components, your "clusters" are not the same. And there are whole > intervals uncovered arbitrarily close to 0, as well as whole intervals > covered. >
Your example differs somewhat from mine. In addition 0 is disconnected from all these intervals by extended intervals. But certainly there is no point connected to 0.
And finally another idea: If the ends of my intervals are multiples of sqrt(2) and if I dont use overlapping intervals, but am satisfied if every rational is covered once only. Then there cannot exist any uncovered irrational that is incommensurable with sqrt(2). How about that?
> >> Thus it makes no sense to say that 0 is the endpoint of > >> a cluster, but not of any particular interval. > >For the proof it does not make a difference whether the intervals are > >connected or could be connected, as long as the limit is defined. > >Important for my proof is only that every neighbourhood of the limit > >contains points of intervals. > > Okay. In my example also, every neighborhood of 0 contains removed > intervals, as well as intervals in C. My question is, why do you see a > contradiction in your example, but none here?
The contradiction would occur if 0 was not the one and only limit point. Every neighborhood of every of my cluster endpoints can contain further cluster endpoints. But there must not be uncovered irrationals without a cluster, and be it as small as you like, between them.
Regards, WM > >
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