An intriguing rationale is provided for the introduction of new keywords that expedite more formal control structures in APL2. Formal definitions of the newly proposed keywords, such as if, then, else, do, and while, are included along with well-developed examples of APL2 with and without their use.

Having talked with Kenneth Iverson about his hopes and thoughts about APL, I know the suggestions in this paper run contrary to some of Iverson’s wisdom and dreams. Nevertheless, the arguments developed here for formalized APL2 control structures are instructive, if not persuasive. I would encourage those interested in this ongoing debate to read this paper and continue the dialogue on the matter with the author at his included email address.