Product Sign

The product of a set of terms typically distinguished by a subscript. For example
\[ \prod_{i=0}^n x_i = x_0 \times x_1 \times \dots \times x_{n-1} \times x_n \]
The product of an infinite number of terms starting at the \(o^{th}\) will be written as
\[ \prod_{i=o}^\infty x_i \]
and, if the number of terms can be implied from the context of the expression, as
\[ \prod_{i} x_i \]