e∈O(g) says, essentially −
e∈o(g) says, essentially −
For every choice of a constant l>0, ∋ a constant a such that the inequality e(x)<k⋅g(x) holds ∀x>a.
e∈O(g) means that e’s asymptotic growth is no faster than g’s, whereas e∈o(g) means that e’s asymptotic growth is strictly slower than g’s. It’s like ≤ versus <.
E.g. x2∈O(x2) x2∉o(x2) x2∈o(x3)