I personally think this exercise is rather odd in the first place. A lot of modern languages seem to have a same base syntax and these comparisons over simple operations is like taking all of the latin based languages and showing all the words that look similar.
Actually Kotlin is just Scala dumbed down by taking out the most powerful and interesting features like higher kinds, implicits, monads or macros. Which makes it just a Java 8 with a bit nicer syntax.
