  We study discontinuous interval maps generated by the action of erasing block
substitutions on the binary expansion. After establishing some general
properties of these maps, we categorize erasing block substitutions in a
hierarchy of classes displaying progressively stronger erasing character. We
investigate how this affects the dynamics of the corresponding interval maps,
showing that the richest dynamical behavior (Devaney and Li-Yorke chaos,
infinite topological entropy) is achieved at a precise step in this hierarchy,
which we name completely erasing substitutions. KEYWORDS: Topological dynamics,
Erasing substitutions; Devaney chaos; Li-Yorke chaos; Topological entropy.
