Kotlin lambda understanding problem

Language Design
2

(Int) -> ((Int) -> Unit) is a method that, given an Int, produces (Int) -> Unit, a function that, given an Int, gives Unit. It would be used like this, with type specifications for clarity:

fun example(lambda1: (Int) -> ((Int) -> Unit)) {
    val lambda2: (Int) -> Unit = lambda1.invoke(5)
    lambda2.invoke(7)

Meanwhile, ((Int) -> (Int)) -> Unit is a method that takes as an argument an (Int) -> Int, and returns Unit. An example might be a mutation on a boxed value:

data class Box(var value: Int) {
    fun mutate(mutation: ((Int) -> Int) -> Unit) {
        value = mutation(value)
    }
}