STEP $(1)$: A DESIGN PROBLEM

Four chairs A$,$ B$,$ C$,$ and D are placed in a row. Each chair may be occupied $("$l$")$ or empty $("0").$ A Boolean function $F$ is $"$l$"$ if and only if there are two or more adjacent chairs that are empty.

$-$Give the truth table defining the Boolean function F

$-$Express F as a minimal sum of products $($SOP$)$

$-$Express F as a minimal product of sums $($POS$)$