Compute product of series with recursive process

Worked first time! Again!!! :)
Compute product of series with iterative process

Had to look back at the design pattern of the sum process to correct
stupid obvious mistakes in this product pattern.
Find pi w/ procedures for factorial & product

Struggled with faulty procedure design owing to mistake in interpreting
the numerator of the approximation for pi/4. The results that led me to
the realization, while debugging the faulty design, are appended at the
bottom of the script.

Note that the underlying product computation is an iterative process.