----------------------------------------------------------------

t_zigzag :: Splay Int
t_zigzag = g
  where
    a = Node Leaf 4 Leaf
    b = Node Leaf 3 a
    c = Node b    5 Leaf
    d = Node Leaf 2 c
    e = Node d    6 Leaf
    f = Node Leaf 1 e
    g = Node f    7 Leaf
t_zigzag :: Splay Int
t_zigzag = g
  where
    a = Node Leaf 4 Leaf
    b = Node Leaf 3 a
    c = Node b    5 Leaf
    d = Node Leaf 2 c
    e = Node d    6 Leaf
    f = Node Leaf 1 e
    g = Node f    7 Leaf
t_zigzag = g
  where
    a = Node Leaf 4 Leaf
    b = Node Leaf 3 a
    c = Node b    5 Leaf
    d = Node Leaf 2 c
    e = Node d    6 Leaf
    f = Node Leaf 1 e
    g = Node f    7 Leaf