If G is any monotone
decomposition of Ra, let HG denote the union of the nondegenerate elements of G,
and let PG denote the projection map from Ra onto the decomposition space R3∕G
associated with G. Suppose that F and G are monotone decompositions of R8 such
that each of Cl(PF[HF]) and Cl(PG[HG]) is compact and 0-dimensional. Then F
and G are equivalent decompositions of R3 if and only if there is a homeomorphism h
from R3∕F onto R8∕G such that
A necessary and sufficient condition for two decompositions to be equivalent is
given. It is shown that there is a decomposition with only a countable number of
nondegenerate elements which is equivalent to the dogbone decomposition, and
several related results are obtained.