The truth table for the circuit given in the fig. is:
$$\left| {\matrix{
A & B & Y \cr
0 & 0 & 1 \cr
0 & 1 & 1 \cr
1 & 0 & 1 \cr
1 & 1 & 1 \cr
} } \right|$$
$$\left| {\matrix{
A & B & Y \cr
0 & 0 & 1 \cr
0 & 1 & 0 \cr
1 & 0 & 0 \cr
1 & 1 & 0 \cr
} } \right|$$
$$\left| {\matrix{
A & B & Y \cr
0 & 0 & 1 \cr
0 & 1 & 1 \cr
1 & 0 & 0 \cr
1 & 1 & 0 \cr
} } \right|$$
$$\left| {\matrix{
A & B & Y \cr
0 & 0 & 0 \cr
0 & 1 & 0 \cr
1 & 0 & 1 \cr
1 & 1 & 1 \cr
} } \right|$$
