
Formal Specifi cations—1 Model Oriented 585
EBNF was seen as a successful formal specifi cation language, although its use is limited to
language syntax defi nition.
VDM-SL is introduced as a specifi cation language and its features, structure, and use are
illustrated with simple examples. An interested reader can try his hand at VDM using the VDM-
SL Toolbox package given on the website.
Key Terms
1. Composites data objects made up from
other data objects, by a specifi c method of
composition, for example, integer arrays.
2. Data types Data type is a type of data
in a computer programming language.
They include primitive types, tuples,