The study of political conflict in legislatures is fundamental to understanding the nature of governance, but also difficult because of changes in membership and the issues addressed over time.

John Kahl, East Peoria mayor This article originally appeared on Journal Star: Opinion: Political rhetoric has divided us.

The n-divided difference of the composite function h := f o g of functions f, g at a group of nodes t₀, t₁, ···, tn is shown by the combinations of divided differences of f at the group of nodes g(t₀) ...