Extended ML is a specification language created by Kahrs, Sannella and Tarlecki based on the ML programming language. It extends the syntax of ML to include axioms, which need not be executable but can rigorously specify the behavior of the program. With this addition the language can be used for stepwise refinement, proceeding gradually from an initial formal specification to eventually yield an executable SML program. Correctness of the final executable SML program with respect to the original specification can then be established by proving the correctness of each refinement step. Extended ML is used for research into and teaching of formal program development and specification, and research into automatic program verification.

Other than being similarly derived from ML, Extended ML is not related to the Extensible ML programming language or to the eXtensible Markup Language.

External links

• Don Sannella - Information about Extended ML

References

• S. Kahrs, D. Sannella, and A. Tarlecki. The definition of extended ML: A gentle introduction. Theoretical Computer Science, 173(2):445-484, 28 Feb 1997