plus#2 0 x12 x12 plus#2 S x4 x2 S plus#2 x4 x2 fold#3 Nil 0 fold#3 Cons x4 x2 plus#2 x4 fold#3 x2 main x1 fold#3 x1 plus#2 2 0 0 S 1 fold#3 1 Nil 0 Cons 2 main 1 INNERMOST hoca/sum.trs