Introduction to Series-Parallel Duality

This is an introduction to the mathematics of series-parallel duality which shows many unexpected applications.

Series-Parallel Duality: Part I: Combating Series Chauvinism

This post describes the duality between the usual (series) addition and the dual parallel addition. This duality is normally considered in electrical circuit theory and combinatorics, but it has a much wider applications. In Part I of this post, the focus is on developing series-parallel dual formulas—in contrast to the usual focus on formulas using only the series sum.