  In \cite{BaDeFePi96} the concept of nondecreasing Dyck paths was introduced.
We continue this research by looking at it from the point of view of words,
rational languages, planted plane trees, and continued fractions.
  We construct a bijection with planted plane trees of height $\le 4$ and
compute various statistics on trees that are the equivalents of nondecreasing
Dyck paths.
