Exactly my point, I'm sure there are benefits, but this example is more suited to Typed languages whereas many functional languages like you say are untyped. And man, I've worked with MIT Scheme in a major commercial software for 5+ years. What a nightmare it was. :(. I mostly understood the functional aspect of the language, but the sea of misplaced brackets and a complete lack of any debugger (at least for our version of it) whatsoever made it one of the worst languages to work with. The biggest irony was, since Scheme is apparently so extensible, they had created a home-grown "Object Oriented Scheme", which implemented only some aspects of OOP and omitted some other very important ones, and it was upto the developer to find out the hard way which ones were omitted! :D