1. DIAGRAMS OF KNOTTED SURFACES
FIGURE 5. A diagram of a knotted sphere
FIGURE 6. A diagram of an unknotted sphere in 4-space
Figure 5 illustrates a broken surface diagram for a knotted sphere (we will
compute that this example is knotted in Chapter 5). Figure 6 illustrates broken
surface diagram for a sphere that we will show is unknotted in Chapter 2.