'''VDM'''

A FormalLanguage based on DenotationalSemantics.

VDM is a generic term indicating different dialects and methodologies originated in the work of HeinzZemanek in the ViennaIbmLaboratory

Currently, VDM-SL (VDM specification language) is the ISO and BSI standard. 
-----
A VDM specification is built upon two models. The representational abstraction, equivalent to a data model, and the operational abstraction, equivalent to a program, that can be done in a declarative of in a imperative way.

-----

Documented in "Systematic Software Development Using VDM" by C.B. Jones

Based around pre- and post- conditions. I assume BertrandMeyer was aware of this when he designed EiffelLanguage.

--PaulHudson (a VDM fan. Once worked in the same company as C. B. Jones, but no VDM used there :-()
----

VDM uses ThreeValuedLogic.
----
CategoryLogic