Let (an)n∈[math]\mathbb{N}[/math] be a sequence and a ∈ [math]\mathbb{R}[/math].[br]We say that the sequence (an)n∈[math]\mathbb{N}[/math] converges to a if and only if[br]∀ε > 0 ∃n_0 ∈ N ∀n ≥ n_0 : |an − a| < ε