Here is my reasoning so far: $A$ is a infinite set and $B$ is a finite subset of $A$, therefore $B\subset A$.

If $C=A\setminus B$ that means that $C$ also is infinite and also, $C\subset A$.

Though, how could one prove that there is a bijection between $A$ and $C$?

  • $\begingroup$ For your reference, 1 and 2. $\endgroup$ – LE Anh Dung Feb 27 '19 at 14:10
  • $\begingroup$ @LeAnhDung Thanks, exactly what I needed. $\endgroup$ – user615771 Feb 27 '19 at 14:14