You people rock. Responses were really helpful and I understand how
the computation goes now.
I see I need to reprogram my eyes to expect lazy evaluation in places
where I am used to one-shot results. I see lazy evaluation is all
around in Haskell builtins.
From a formal point of view
I am learning Haskell with Programming in Haskell (an excellent
book BTW).
I have background in several languages but none of them has lazy
evaluation. By now I am getting along with the intuitive idea that
things are not evaluated until needed, but there's an example I don't
understand
