The theory of developmental systems and languages is the result of
an infusion of ideas from developmental biology into formal language theory.
It has become a very actively investigated topic in the last few years,
and produced many results of interest both for the formal language theorist
and for the biologist.
The purpose of our book is to provide a self-contained text
on this new important scientific area, which nevertheless provides
an exhaustive survey of the state-of-the-art at the time of writing.
The book consists of an introduction followed by three main sections.
The biological motivation behind our study is to be found in the introductory section.
Parts I and II form the main body of the work.
They provide a rather formal presentation of the theory of developmental languages
and developmental sequences respectively.
Only concise references are given to biological motivation inside these parts,
and some of the topics are investigated more for their intrinsic
formal language theoretical interest than for their relevance to biology.
In Part III we return to a less formal discussion of topics whose biological motivation
is more apparent. Having read the book, the reader should refer back to
the introduction to see how the formal theory meshes with
the underlying biological questions.
