Definition:Cauchy's Criterion for Products

Definition
Let $\mathbb K$ be a field with absolute value $\left\vert{\cdot}\right\vert$.

Let $(a_n)$ be a sequence of elements of $\mathbb K$.

The infinite product $\displaystyle \prod_{n \mathop = 1}^\infty a_n$ satisfies Cauchy's criterion :


 * $\displaystyle \forall \epsilon \in \R_{>0}: \exists N \in \N: \forall m, n \in \N: m\geq n \ge N: \left|{\prod_{k = n}^m a_n - 1}\right| < \epsilon$

Also see

 * Convergent Product Satisfies Cauchy Criterion