From an infinite sequence a₁, a₂, a₃,…, an infinite product a₁ a₂ a₃…can be formed and denoted by

Let P_n be the nth partial product, so that

If P_n tends to a limit P as n → ∞, then P is the value of the infinite product. For example,

has the value $\frac{1}{2}$, since it can be shown that P_n = (n + 1)/2n and $P_n\to \frac{1}{2}$.