The paper's premise is a broad one. Its authors are hard-core functional programmers, but believe that eventually students have to learn something beyond just p

The paper's premise is a broad one. Its authors are hard-core functional programmers, but believe that eventually students have to learn something beyond just pure FP. Too often, introductory curricula are designed with a "screw what happens later" attitude, which ends up being self-defeating. The paper's point is that they should instead provide a gradual progression, and that this progression should be over at least two different time-scales.