val tripleIt3: (Int) -> Int = { i: Int -> i * 3 }

// Simplify things with it
val quadItIt3: (Int) -> Int = { it * 4 }

fun doubleIt3(i: Int): Int = i * 2

val doubleIt3: (Int) -> Int = ::doubleIt3

// Higher-order function as a parameter
fun func3(i: Int, func: (Int) -> Int): Int = func.invoke(i)