Definition:Asymptotic Equality/Sequences/Definition 3

Definition
Let $\left \langle {a_n} \right \rangle$ and $\left \langle {b_n} \right \rangle$ be sequences in $\R$.

$\left \langle {a_n} \right \rangle$ is asymptotically equal to $\left \langle {b_n} \right \rangle$ :
 * $a_n - b_n = o(a_n)$

where $o$ denotes little-o notation.