class MyRange1() : Range { override val start: Int get() = 0 override val end: Int get() = 0 override fun contains(item: Int) = true } class MyRange2() { fun contains(item: Int) = true } fun box(): String { if (1 in MyRange1()) { if (1 in MyRange2()) { return "OK" } return "fail 2" } return "fail 1" }