kotlin for loop is weird

gistfile1.kt

//normal for in
fun fizzBuzz(start: Int = 1, end: Int = 15) {
    for(foobar in start..end) {
        println(when {
            foobar % 5 == 0 && foobar % 3 == 0 -> "FizzBuzz"
            foobar % 3 == 0 -> "Fizz"
            foobar % 5 == 0 -> "Buzz"
            else -> "$foobar"
        })
    }
}

//equivalent to for(start = 1; start < end; start+=2) ?
fun fizzBuzz(start: Int = 1, end: Int = 15) {
    for(foobar in start..end step 2) {
        println(when {
            foobar % 5 == 0 && foobar % 3 == 0 -> "FizzBuzz"
            foobar % 3 == 0 -> "Fizz"
            foobar % 5 == 0 -> "Buzz"
            else -> "$foobar"
        })
    }
}

//equivalent to for(end = 15; end > start; end-=2) ?
fun fizzBuzz(start: Int = 1, end: Int = 15) {
    for(foobar in end downTo start step 2) {
        println(when {
            foobar % 5 == 0 && foobar % 3 == 0 -> "FizzBuzz"
            foobar % 3 == 0 -> "Fizz"
            foobar % 5 == 0 -> "Buzz"
            else -> "$foobar"
        })
    }
}