Consider the following boolean formula in $4$ variables, A$,$ B$,$ C$,$ and D:

F$($A$,$ B$,$ C$,$ D$)=($A

$+$ C

$$

$)($A $+$ B $+$ C$)($A $+$ C $+$ D$$

$)($B

$+$ C

$+$ D$)$