
(c) $\ \ Y = \overline{AB} + \overline{BA}\ $
$\left. \ \begin{array}{r}
A = 0\ B = 0 \\
\overline{A} = 1\ \overline{B} = 1
\end{array} \right\rbrack Y = 0$
$\left. \ \begin{array}{r}
A = 0\ B = 1 \\
\overline{A} = 1\ \overline{B} = 0
\end{array} \right\rbrack Y = 1$
$\left. \ \begin{array}{r}
A = 1\ B = 0 \\
\overline{A} = 0\ \overline{B} = 1
\end{array} \right\rbrack Y = 1$
$\left. \ \begin{array}{r}
A = 1\ B = 1 \\
\overline{A} = 0\ \overline{B} = 0
\end{array} \right\rbrack Y = 0$