In such topological vector spaces one can consider series of vectors. The infinite sum ∑ ∑ i = 1 ∞ ∞ f i = lim n → → ∞ ∞ f 1 + ⋯ ⋯ + f n denotes the limit of the corresponding finite partial sums of the sequence f 1 , f 2 , … … of elements of V . For example, the f i could be (real or complex) functions belonging to some function space V , in which case the series is a function series. The mode of convergence of the series depends on the topology imposed on the function space. In such cases, pointwise convergence and uniform convergence are two prominent examples.