Wednesday, 28 June 2017

cardinals - Cardinality of infinite sequences of 0 and 1 geq|mathbbR|

Think of all infinite sequences of 0s and 1s. Let the set be S. I want to prove that the cardinality |S| is greater than or equal to |R|. I think it is useful to use the fact that the set T of reals in (0,1) has the same cardinality as R. If I can create an injective function from S to T then it would imply |S|=|T|=|R|. I think of taking the the infinite number in S, typically 10011001... and map to the number in T with that decimal expansion, so 0.10011001.... Then wouldn't that be an injection?

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real analysis - How to find limhrightarrow0fracsin(ha)h

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