(==) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) == True
(==) (Node 4 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) == False

(<)  (Node 4 (Leaf 2) (Leaf 2)) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) == True
(<)  (Node 4 (Leaf 2) (Leaf 3)) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) == False

(<=) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) == True
(<=) (Node 4 (Leaf 2) (Leaf 3)) (Node 5 (Node 3 (Leaf 1) (Leaf 2)) (Leaf 3)) == True

lsortIncr [3,1,3,5] == [1,3,3,5]
lsortDecr [3,1,3,5] == [5,3,3,1]

tsortIncr (Node 4 (Leaf 2) (Leaf 3)) == (Node 3 (Leaf 2) (Leaf 4))
tsortDecr (Node 4 (Leaf 2) (Leaf 3)) == (Node 3 (Leaf 4) (Leaf 2))

ulsortIncr [3,1,3,5] == [1,3,5]
ulsortDecr [3,1,3,5] == [5,3,1]

utsortIncr (Node 4 (Node 3 (Leaf 2) (Leaf 2)) (Leaf 3)) == (Node 3 (Leaf 2) (Leaf 4))
utsortIncr (Node 3 (Node 3 (Leaf 2) (Leaf 2)) (Leaf 3)) == (Node 2 (Leaf 2) (Leaf 3))

utsortDecr (Node 4 (Node 3 (Leaf 2) (Leaf 2)) (Leaf 3)) == (Node 3 (Leaf 4) (Leaf 2))
utsortIncr (Node 3 (Node 3 (Leaf 2) (Leaf 2)) (Leaf 3)) == (Node 2 (Leaf 2) (Leaf 3))