g Cons x xs y Cons x xs h Nil y h Nil y h Cons x xs y f Cons x xs y g Nil y h Nil y f Nil y g Nil y f Cons x xs y h Cons x xs y sp1 x y f x y r x y x g 2 Cons 2 h 2 Nil 0 f 2 sp1 2 r 2 INNERMOST