This is a text description of Figure 2-12, "Moving a Non-Isolated Edge". It illustrates the movement of non-isolated edge E7, as explained in text before and after the illustration.

The topology consists of two adjacent rectangular faces, F1 and F3, separated by edge E7. Face F1 is bounded by edges E1, E7, E5, and E6; and face F3 is bounded by edges E2, E3, E4, and E7.