[lukasLansky]

Good question. :-) I guess there definitely would be cases where the programmer would be restricted in what they want to do -- this is a nature of type systems. For example, I guess following code would not compile:

var f = (n) => n / 5; f = (n) => 5 / n;

What I hope for is that usual patterns would survive in a convenient manner. For example, calling function with function argument that is evaluated inside this function is something that could be handled by language without too many problems.