Here is the cover of the latest one:

1. Folding over recursively defined data structures for natural numbers and lists. Folding Cheat Sheet #1

2. Programmatic and Mathematical definitions of right fold and left fold. Folding Cheat Sheet #2

3.The universal property of fold Folding Cheat Sheet #3

4. For functions that can be defined both as an instance of a right fold and as an instance of a left fold, one may be more efficient than the other. Let’s look at the example of a function ‘decimal’ that converts a list of digits into the corresponding decimal number. Folding Cheat Sheet #4

5. Folding a list right and left using Cons and Nil results in the identity and reverse functions. Folding Cheat Sheet #5

6. Left and right folds and tail recursion. Folding Cheat Sheet #6

7. The three duality theorems of fold. Folding Cheat Sheet #7