Solved Problem 4 in Haskell
Use Prelude's compare instead of signum
Remove as-pattern for readability
Refactor Problem 4 logic to avoid one branch of recursion
Rename the primary logic function in Problem 4
Replace map with a list comprehension
Remove unnecessary parentheses
Parameterize the multiplication table for Problem 4
Solve Problem 5 in Haskell
Use lcm instead of testing all multiples of 19*20
Solve Problem 6 in Haskell