Exercise 04-1: Split an even-lengthed list into two halves
Exercise 04-2: Safetail, like tail but mapping empty list to itself
Exercise 04-3: Logical disjunction operator (||) implementations
Exercise 04-4: Logical conjunction operator (&&) implementations
Exercise 04-6: Curry 'mult x y z' in terms of lambda expressions
Extra exercise 04-1: Implement 'remove n xs'
Extra exercise 04-2: Guess the type
Extra exercise 04-3: A suitable definition for the following types
Caesar Cipher: lowerChar2Int
Caesar Cipher: int2LowerChar
Caesar Cipher: shiftLowerChar
Caesar Cipher: encode
Caesar Cipher: decode
Caesar Cipher: freqTable
Caesar Cipher: freqs
Caesar Cipher: chiSquare
Caesar Cipher: rotate
Caesar Cipher: crack