Let $f : \{ 0, 1 \} \to \{ a, b \}$ be a D18: Map such that
| (i) | \begin{equation} f(0) = a \end{equation} |
| (ii) | \begin{equation} f(1) = b \end{equation} |
| (iii) | \begin{equation} A : = \{ 0, 1 \} \end{equation} |
| (iv) | \begin{equation} B : = \{ b \} \end{equation} |
Then
| (1) | $f$ is a D468: Bijective map |
| (2) | \begin{equation} f^{-1}(B) \subseteq A \end{equation} |
| (3) | \begin{equation} f(A) \not\subseteq B \end{equation} |