In 1983, David H. D. Warren designed an abstract machine for the execution of Prolog consisting of a memory architecture and an instruction set [War83]. This design became known as the Warren Abstract Machine (WAM) and has become the de facto standard target for Prolog compilers.

In [War83], Warren describes the WAM in a minimalist's style, making understanding very difficult for the average reader, even with a foreknowledge of Prolog's operations. Too much is left untold, and very little is justified in clear terms. (David H. D. Warren's confides privately that he "felt [that the WAM] was important, but [its] details unlikely to be of wide interest. Hence, [he used a] 'personal notes' style.") This has resulted in a very scant number of WAM aficionados who could boast understanding the details of its workings.

References

• [War83] David H. D. Warren. An abstract Prolog instruction set. Technical Note 309, SRI International, Menlo Park, CA, October 1983.

External links

• Hassan Aït-Kaci's book "Warren's Abstract Machine: A Tutorial Reconstruction" is out of print. The author has made it available online and free to use for non-commercial purposes.