$2$ Consider the ALU depicted below

$(BB$ is either $B$ or $\frac{?}{\text{b}\text{a}\text{r}}(B))$

As a symbol

As a combinational circuit

According to the control signal $F_{2\text{:}0},$ it calculates a function:

$\backslash$table$[[F_{2\text{:}0},$Function$],[000,$A AND B$],[001,$A OR B$],[010,$A $+$ B$],[011,$not used$],[100,$A AND $\frac{?}{\text{b}\text{a}\text{r}}(B)$