 VDM-SL: a Tutorial
started 8/22/2002; 3:53:48 AM - last post 8/22/2002; 3:53:48 AM
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jon fernquest - VDM-SL: a Tutorial 
8/22/2002; 3:53:48 AM (reads: 1948, responses: 0)
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| VDM-SL: a Tutorial |
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The ill-defined semantics of PL/I provided the initial impetus
behind VDM which was used in the design of ADA. Z was a
product of a VDM splinter group.
Online tutorial includes some interesting examples
like a virtual keyboard for Indian script and regular expression specifications.
Chapters on "sets, sequences, maps, function composition, refinement, and modules."
Note VDM was defined before object oriented programming came along.
The definition of PL/I was done using a notation specially developed for the task.
It occupied several hundred pages of fine print and was only really intended
to be of use to implementers of PL/I compilers....
A number of the people involved in that specification project had realised
part way through that 'there had to be a better way!' ...people...
were beginning to formalise the theory behind the concepts of denotational
semantics....
Work on designing and specifying Ada was going on at the same
time and a team ...started to develop
a specification for Ada in a notation which differs in visible syntax but
was essentially the same as that now known as vdm-sl. At that time
the notation had not received any formal definition itself although theorists
in several places realised that there was something important in being able
to specify activities in a formal way....
To cut a long story short, it was in the early 1990s that work
...began on formal definition of vdm-sl itself. Some years and a lot of
meetings later a group at Oxford broke off to develop another
formal specification language based around another form of
mathematical logic - and Z was born.
Posted to history by jon fernquest on 8/22/02; 3:59:23 AM
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