On Jul 14, 2007, at 1:36 AM, Trevor Squires wrote: > sum([H|T]) -> H + sum(T); > sum([]) -> 0. > > "Oh my god! Won't that blow the stack?" - well, I *think* it's > okay because of something called 'tail-recursion' - but like you, I > don't know what I don't know. For what it's worth: the function definition is "tail-recursive" and the technique used by the compiler/interpreter to prevent stack overflow is called "tail-recursion elimination". That is, the compiler/interpreter transforms the recursion into an iteration (which is relatively easy to do for tail-recursive functions). Regards, Morton