Working with functions

1 2 3 4 5 6 7 8 | ```
add :: Int -> Int
add x y = x + y
multiply :: Int -> Int -> Int
multiply x y = x * y
f :: Int -> Int
f x = 2 * x + 1
``` |

Note that f is a function that multiplies its argument by 2 followed by incrementing it by 1. Note that instead of reusing the existing add and multiply functions, we had declared an entirely new function.