[add image: A and B each passed through a NOT gate, then into a NOR gate] $Y = \overline{\bar{A} + \bar{B}} = \bar{\bar{A}} \cdot \bar{\bar{B}} = A \cdot B$ (AND gate) Truth table: (0,0) → 0, (0,1) → 0, (1,0) → 0, (1,1) → 1