deletions | additions       diff --git a/For_any_set_A_show__.tex b/For_any_set_A_show__.tex  index f34a88c..ecc336d 100644  --- a/For_any_set_A_show__.tex  +++ b/For_any_set_A_show__.tex 
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For any set A, show there is a one-to-one correspondence between the $\mathcal{P}(A)$ of all subsets of A and the set $2^A$ of all functions $\alpha: A\to \{0,1\}$. (Hint: use the indicator function of a set).  \\ Notation: For sets A, $\underline{2}$: 2^A set of all function $p(A):A $P(A):A  \rightarrow \underline{2}$, \\We have $\underline{2}$ := \{0,1\} and $2^A$ := set of all functions   \\ \[ p(A) P(A)  : A \rightarrow \{0,1\} \]