VDM-SL
Vienna Development Method Specification Language. (Also known as Meta-IV.)
A model-oriented specification language upon which the Vienna Development Method is based.
"The Vienna Development Method: The Meta-Language", D. Bjorner et al eds, Lecture Notes in Computer Science 61, Springer-Verlag, 1978.
"The VDM-SL Reference Guide", J. Dawes, Pitman 1991.
Systematic Software Development Using VDM, C. B. Jones, Prentice-Hall 1989.
ISO draft Apr 1993.
BSI/VDM