Programming Pearls, 2nd Edition

Column 4: Writing Correct Programs

In the late 1960’s people were talking about the promise of programs that verify the correctness of other programs. Unfortunately, in the intervening decades, with precious few exceptions, there is still little more than talk about automated verification systems. In spite of unrealized expectations, though, research on program verification has given us something far more valuable than a black box that gobbles programs and flashes “good” or “bad” — we now have a fundamental understanding of computer programming.

The purpose of this column is to show how that fundamental understanding can help real programmers write correct programs. One reader characterized the approach that most programmers grow up with as “write ...