Program derivation
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In computer science, program derivation is the derivation a program from its specification, by mathematical means.
To derive a program means to write a formal specification, which is usually non-executable, and then apply mathematically correct rules in order to obtain an executable program. The program thus obtained is then proved correct by construction.
The approach usually taken in Formal verification is to first write a program, and then provide a proof that it conforms to a given specification. The main problems with this are that
- the resulting proof is long and cumbersome
- no insight is given as to how the program was developed; it appears "like a rabbit out of a hat"
Program derivation tries to remedy these shortcomings by
- keeping proofs short, by development of appropriate mathematical notations
- discovering the program by manipulation of the specification
Terms that are roughly synonymous with program derivation are: transformational programming, algorithmics, deductive programming.
See also
References
- Edsger Dijkstra, Wim H. J. Feijen, A Method of Programming, Addison-Wesley, 1988, 188 pages
- Edward Cohen, Programming in the 1990's, Springer-Verlag, 1990
- Anne Kaldewaij, Programming: The Derivation of Algorithms, Prentice-Hall, 1990, 216 pages
- David Gries, The Science of Programming, Springer-Verlag, 1981, 350 pages
- A.J.M. van Gasteren. On the Shape of Mathematical Arguments. Lecture Notes in Computer Science #445, Springer-Verlag, 1990. Teaches how to write proofs with clarity and precision.