VDM-10 Language Manual

Chapter 17
Top-level Specification (VDM-SL)
In the previous sections all the VDM-SL constructs such as types, expressions, statements, functions
and operations have been described. A number of these constructs can constitute a top-level
VDM-SL specification. A top-level specification can be created in two ways:
1. The specification is split into a number of modules which are specified separately, but can
depend on each other.
2. The specification is specified in a flat manner, i.e. no modules are used.
Thus, a complete specification, or document, has the following syntax.
Syntax: document = any module, { any module }
| definition block, { definition block } ;
any module = module ;
17.1 A Flat Specification
As said, a flat specification does not use modules. This means that all constructs can be used
throughout the specification. In the flat case, a document has a syntax of:
document = . . .
| definition block, { definition block } ;
definition block = type definitions
| state definition
| value definitions
| function definitions
| operation definitions ;
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