What is the criteria for building a cotree from a cograph? All I really know is that the nodes from a cograph G are included as leaves in the cotree, and the internal nodes are labelled alternatingly from 0 and 1. More specifically, I don't understand the leaf groupings. I've included an example below to illustrate the problem.

[![A cograph and it's corresponding cotree](https://i.stack.imgur.com/ZSs50.png)](https://i.stack.imgur.com/ZSs50.png)