How to solve a tricky problem using a picture.

In the last article of this three-part series, Phil Wilson shows how simple graphs can tell you a lot about the economy — and not only in Slugworld.

In last issue's Graphical methods I Phil Wilson used maths to predict the outcome of a cold war in slug world. In this self-contained article he looks at slug world after the disaster: with only a few survivors and all infra-structure destroyed, which species will take root and how will they develop? Graphs can tell it all.

To arm or to disarm? This is the question in Phil Wilson's article, which explores the maths behind a cold war in slug world.