The description of the module organization does not match the diagram.

Broadly, the modules are organized into 3 groups:

• Infrastructure (bottom rung, and bottom row of boxes) – This is at the top of the diagram
• Content (middle rung, and top row of boxes)
• Reasoning (top rung) – This is at the bottom of the diagram

Dependencies between the modules are mainly downwards, with some horizontal dependencies.  – It might be clearer to add clarification such as ie. Level 2 builds on Level 1.