Figure 9: A Re-Routing Event

The lower half of the figure should be titled "Configuration after failure of
E1-F link".

In the lower diagram, D2 should have a '_' as the first character of its link to E2.

In both diagrams, A should have a '_' as the first character of its link to B.

In the lower diagram, is there a space missing between the top line of the box
around B and the . to its right (i.e. +-+. should be +-+ .)?