Multime marginita de numere reale cu exact 3 puncte limita

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Cezar Lupu
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Multime marginita de numere reale cu exact 3 puncte limita

Post by Cezar Lupu »

Sa se construiasca o multime marginita de numere reale cu exact 3 puncte limita.
An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says “You’re all idiots”, and pours two beers.
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Dragos Fratila
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Post by Dragos Fratila »

Daca am inteles bine problema:

Fie \( A=\{0,1,1/2,1/4,1/8,...\} \). Are punct limita doar pe 0.

Multimea o alegi atunci ca fiind \( A\cup (A+3)\cup (A+7) \) si va avea ca puncte limita pe 0,3,7...
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