  Most of the results in the paper for Patricia tries have earlier been proved
by Jaspar Ischebeck.
  We study the distribution of fringe trees in Patricia tries and compressed
binary search trees; both cases are random binary trees that have been
compressed by deleting vertices of outdegree 1 so that they are random full
binary trees. The main results are central limit theorems for the number of
fringe trees of a given type, which imply quenched and annealed limit results
for the fringe tree distribution; for Patricia tries, this is complicated by
periodic oscillations in the usual manner. We also consider extended fringe
trees. The results are derived from earlier results for uncompressed tries and
binary search trees. In the case of compressed binary search trees, it seems
difficult to give a closed formula for the asymptotic fringe tree distribution,
but we provide a recursion and give examples.
