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I had questions if exist A $\neq \emptyset $ that |A|=|P(A)|

And my doubt is if $ |2^{\mathbb{R}}|=|\mathbb{R}|$?

aiki93
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1 Answers1

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The cardinality of the powerset $P(A)$, which is $|2^A|$, is always strictly greater than the cardinality of $A.$

$$\;|A| \lt |P(A| = \left|2^{A}\right|$$

So it follows that $|\mathbb R| \lt \left|2^{\mathbb R}\right|$.

What is true is that $|\mathbb R| = \left|2^{\mathbb Z}\right|.$

amWhy
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