Monday, 12 October 2015

elementary set theory - Is the sets of all maps from mathbbN to mathbbN countable?

Is the sets of all maps from N to N countable?



Attempts: I think it is uncountable. Consider P(N) where P(A) denote as the power sets of A. We know that P(N) is uncountable. Moreover, by the axiom of choice, for any non empty set, we know that there exist a function f:P(N)N . Note that P(N) have uncountable many elements and since each f belongs to the set of all mapping from N to N so there exist infinite uncountably elements and hence this set are uncountable. Is my attempt work??

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