From the Intro, the prerequisites: "I try to keep the required background knowledge to a minimum in this book. I will assume familiarity with the material from

From the Intro, the prerequisites: "I try to keep the required background knowledge to a minimum in this book. I will assume familiarity with the material from usual discrete math and logic courses taken by undergraduate computer science majors, and I will assume that readers have significant experience programming in one of the ML dialects, in Haskell, or in some other, closely related language. Experience with only dynamically typed functional languages might lead to befuddlement in some places, but a reader who has come to understand Scheme deeply will probably be fine." Then it is not for me, I am still struggling with Haskell.