Structured Programming With and Without GO TO Statements

While “Dijkstra flow-chart schemes” (built out of assignment statement schemes by means of composition, if-then and whiledo) are simple and perspicuous, they lack the descriptive power of flow-chart schemes (provided additional “variables” are not permitted). On the other hand, the analogous multiexit composition binary alternation-conditional iteration (CACI) schemes introduced below, which are virtually as simple and perspicuous as Dijkstra schemes, describe exactly the same computational processes as flow-chart schemes (without the aid of additional variables).Theorem 9.1 makes contact with “reducible flow-graphs” an active area in its own right.