A constructive approach to the problem of program correctness

As an alternative to methods by which the correctness of given programs can be established a posteriori, this paper proposes to control the process of program generation such as to produce a priori correct programs. An example is treated to show the form that such a control might then take. This example comes from the field of parallel programming; the way in which it is treated is representative of the way in which a whole multiprogramming system has actually been constructed.