val list = listOf("a", "b", "c", "d")

// *** before: ***
val rangeOld = 0 until list.size
val lettersOld = 'a' until 'd'

// *** in version 1.9: ***
val range = 0..<list.size          // the ..< operator became Stable
val letters = 'a'..<'d'
val fractions: OpenEndRange<Double> = 0.0..<1.0

fun main() {
    for (i in 0..<list.size) print(list[i])
    println()
    println(9 in 0..<10)           // true
    println(10 in 0..<10)          // false, the end is excluded
    println(1.0 in fractions)      // false
    println("$rangeOld $range $lettersOld $letters")
}