schicht (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) 1 == [3,9]
schicht (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) 2 == [5,7,11]

abschneiden (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) 1 == (Node 1 (Node 3 Nil Nil) (Node 9 Nil Nil))
abschneiden (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) 5 == (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil))

ausschneiden (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) (-2) 3 == [[],[],[1],[3,9],[5,7,11],[]]
ausschneiden (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) 1 2 == [[3,9],[5,7,11]]

summe (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) (-2) == 0
summe (Node 1 (Node 3 (Node 5 Nil Nil) (Node 7 Nil Nil)) (Node 9 (Node 11 Nil Nil) Nil)) 1 == 13