Fig. 25.

For degree $\mathbf{p}=(3,3)$, the element $\check{Q}$ (light gray) is bisected in more than two Bézier elements after the bisection of ${\check{Q}}^{\prime }$ (dark gray). The element ${\check{Q}}^{\prime }$ is bisected by the thick black line in direction $s=1$, and it is translated with respect to $\check{Q}$ in direction $\tilde{s}=2$