An Executable Semantics for a Formalized
	       Data Flow Diagram Specification Language
				  by
	   Tim Wahls, Albert L. Baker, and Gary T. Leavens

While traditional Data Flow Diagrams (DFDs) are popular, they lack the
formality needed in a good specification technique. We provide an
executable semantics for a subset of RT-SPECS, a formalization of
DFDs, using the programming language Standard ML. RT-SPECS is a formal
notation for specifying concurrent and real-time software that relies
on model-based specification of abstract datatypes. Processes are
specified using assertions rather than algorithms. Because our
semantics of RT-SPECS is written in SML, it is also an interpreter,
yielding a directly executable specification language.

Categories and Subject Descriptors:
D.2.1 [Software Engineering] Requirements/Specifications | languages;
D.2.2 [Software Engineering] Tools and Techniques | computer-aided software engineering (CASE);
D.2.m [Software Engineering] Miscellaneous | rapid prototyping
General Terms: Specification, Design, Prototyping, Formal Semantics
Additional Key Words and Phrases: Data Flow Diagrams (DFDs), Standard
ML, executable specification, literate programming, operational
semantics, specification language semantics, RT-SPECS, Structured Analysis (SA)