  In extension theory, in particular in dimension theory, it is frequently
useful to represent a given compact metrizable space X as the limit of an
inverse sequence of compact polyhedra. We are going to show that, for the
purposes of extension theory, it is possible to replace such an X by a better
metrizable compactum Z. This Z will come as the limit of an inverse sequence of
triangulated polyhedra with simplicial bonding maps that factor in a certain
way. There will be a cell-like map from Z to X, and we shall show that if K is
a CW-complex which is an absolute extensor for X, then K is also an absolute
extensor for Z.
