Have you read Iverson’s works, “Notation as a tool of thought” or “the description of finite sequential processes”? Both are available on the jaoftware website,

Have you read Iverson’s works, “Notation as a tool of thought” or “the description of finite sequential processes”? Both are available on the jaoftware website, and give a good (in my biased opinion) introduction to APL I say biased because I had used APL and K extensively before reading them - they might seem less clear without this background, though it should be noted they are both considered classics by non APLers. Personally, TDOFSP contains the simplest most straightforward description of the simplex algorithm for linear programming/planning that I’ve encountered.