Polyglot FP for Fun and Profit – Haskell and Scala
https://fpilluminated.com/deck/238
This deck is about the leap_year function shown in x.com, i.e.
leap_year :: Integral a => a -> Bool
leap_year = liftA2 (>) (gcd 80) (gcd 50)
Given an integer representing a year, the function returns a boolean indicating if that year is a leap year.
See why the Function Applicative allows the leap_year function to be defined as shown in that tweet.