The expressiveness of "basic control flow constructs" was only formally established 1966; four years after Knuth started TAoCP and two years before the first vo

The expressiveness of "basic control flow constructs" was only formally established 1966; four years after Knuth started TAoCP and two years before the first volume would be complete; also two years before the starting salvos of the fight over whether structured programming was a good engineering decision (as opposed to merely a choice of mathematical formalism) or not. Moreover, the whole point of the series is to discuss foundational matters. Today, for a variety of reasons, we tend to assume structured programming as an unalloyed good. But given both the physical and mathematical structure of computing it's not an obvious theorem; it has even less obvious consequences for pedagogy and engineering; and if we are to address foundational matters, we need to understand both sides of the transformation.