An example is given of an
u.s.c. decomposition in which no disk in E3 maps onto a disk under the natural
projection map P, and, furthermore, the decomposition space E3∕G is homeomorphic
to E3. Each nondegenerate element is a tame arc. The image P(H) of the
set of nondegenerate elements is 0-dimensional, although Cl P(H) is E3.
The basic construction used is called a knit Cantor set of nondegenerate
elements.