
3.5 Models of Computation and Programming 217
Unified Modeling Language (UML) notation describes the language: the top-
level construct in the language is
SW, which includes models of type Block, and
so on. The right side of the figure shows some well-formedness rules described
as Object Constraint Language (OCL) expressions.
Karsai et al. argue that embedded systems, because they are complex and
must be reliable, should be designed in languages with well-defined semantics,
not simply by informal English descriptions. One common method for specif-
ying the semantics of a domain-specific modeling language is metamodeling,
which writes the semantics in ...