1.2. KNOTTED SURFACE DIAGRAMS 5
3. The crosscap diagram of an embedded projective plane
4. The diagram of an embedded Klein Bottle
Here are some examples of broken surface diagrams. Figure 3 contains a broken
surface illustration of a cross-cap. Figure 4 illustrates a broken surface diagram of
the Klein bottle. In the next section we will describe how to obtain broken surface
diagrams from knotted surfaces in 4-space.