walk#1 Leaf x2 cons_x x2 walk#1 Node x5 x3 comp_f_g walk#1 x5 walk#1 x3 comp_f_g#1 comp_f_g x4 x5 comp_f_g x2 x3 x1 comp_f_g#1 x4 x5 comp_f_g#1 x2 x3 x1 comp_f_g#1 comp_f_g x7 x9 cons_x x2 x4 comp_f_g#1 x7 x9 Cons x2 x4 comp_f_g#1 cons_x x2 comp_f_g x5 x7 x3 Cons x2 comp_f_g#1 x5 x7 x3 comp_f_g#1 cons_x x5 cons_x x2 x4 Cons x5 Cons x2 x4 main Leaf x4 Cons x4 Nil main Node x9 x5 comp_f_g#1 walk#1 x9 walk#1 x5 Nil walk#1 1 Leaf 1 cons_x 1 Node 2 comp_f_g 2 comp_f_g#1 3 Cons 2 main 1 Nil 0 INNERMOST hoca/flatten.trs