$7\mathrm{.}22.$ Two sequences $a_n$ and $b_n$ are said to be asymptotic to each other if their ratio

$\frac{a_n}{b_n}$ tends to $1$ as $n$ tends to infinity. If $a_n$ and $b_n$ are asymptotic to each other, does

their difference $a_n-b_n$ tend to $0?$