The question of existence of sets $x,y$ such that
$$|x|<|y| \wedge |P(x)|=|P(y)|$$
is known to be independent of $\text{ZFC}$!
But are there known examples of sets fulfilling the above condition that necessitates violation of choice?
The question of existence of sets $x,y$ such that
$$|x|<|y| \wedge |P(x)|=|P(y)|$$
is known to be independent of $\text{ZFC}$!
But are there known examples of sets fulfilling the above condition that necessitates violation of choice?