This book summarizes work done by the authors under theEsprit Tool Use project (1985-1990), at GMD in Karlsruhe and
at Berlin University of Technology. It provides a
comprehensive description of the generic development
language Deva designed by the authors. Much of the research
reported in this monograph is inspired by the work of Michel
Sintzoff on formal program development; he contributed an
enlightening Foreword.
Deva is essentially a typed functional language with certain
deduction rules. The difference with ordinary languages is,
of course, the application domain: the types serve here to
express propositions such as specifications or programs,
rather than just data classes. Its practical applicability
was tested on several non-trivial case studies. The whole
book is written using the DVWEB system, a WEB for Deva,
beeing implemented at the Berlin University of Technology.

Informal introduction to Deva.- Stepwise definition of Deva.- Formalization of basic theories.- Case study on VDM-style developments.- Case study on algorithm calculation.- Conclusion.