max expr size  =    5
  |- on ineqs  =    4
  |- on conds  =    4
max  #-tests   =  500
min  #-tests   =   25  (to consider p ==> q true)
max  #-vars    =    2  (for inequational and conditional laws)

_ :: Bool
_ :: Int
_ :: [Int]
False :: Bool
True :: Bool
[] :: [Int]
(:) :: Int -> [Int] -> [Int]
(++) :: [Int] -> [Int] -> [Int]
elem :: Int -> [Int] -> Bool
ordered :: [Int] -> Bool
all :: (Int -> Bool) -> [Int] -> Bool
insert :: Int -> [Int] -> [Int]
sort :: [Int] -> [Int]
(==) :: Int -> Int -> Bool
(<=) :: Int -> Int -> Bool
(<) :: Int -> Int -> Bool
(==) :: Bool -> Bool -> Bool
(==) :: [Int] -> [Int] -> Bool

      ordered (sort xs) == True
  ordered (insert x xs) == ordered xs
    (xs == insert x xs) == False
    ([] == insert x xs) == False
        (xs == sort xs) == ordered xs
       elem x (sort xs) == elem x xs
        (sort xs == []) == (xs == [])
   all (x ==) (sort xs) == all (x ==) xs
    all (x <) (sort xs) == all (x <) xs
          all (x <=) xs == ordered (x:sort xs)
ordered (xs ++ sort xs) == ordered (xs ++ xs)
ordered (sort xs ++ xs) == ordered (xs ++ xs)
   elem x (insert y xs) == elem x (y:xs)
         sort (sort xs) == sort xs
            insert x [] == [x]
        sort (xs ++ ys) == sort (ys ++ xs)
     sort (insert x xs) == insert x (sort xs)
            sort (x:xs) == insert x (sort xs)
   sort (xs ++ sort ys) == sort (xs ++ ys)
 insert x (insert y xs) == insert y (insert x xs)
        insert x (x:xs) == x:x:xs
           insert x [y] == insert y [x]

  xs == sort ys ==> ordered xs
        sort xs <=  xs
    insert x xs <=  x:xs
      x:sort xs <=  x:xs
  xs ++ sort ys <=  xs ++ ys
  sort xs ++ ys <=  xs ++ ys
    sort (x:xs) <=  insert x xs
sort (xs ++ ys) <=  xs ++ sort ys
sort (xs ++ ys) <=  sort xs ++ ys
  sort xs ++ xs <=  xs ++ sort xs

     all (x <=) xs ==>         insert x xs == x:xs
ordered (ys ++ xs) ==>       ys ++ sort xs == sort (xs ++ ys)
ordered (ys ++ xs) ==>       sort ys ++ xs == sort (xs ++ ys)
     all (x <=) xs ==>           x:sort xs == sort (x:xs)
         elem x xs ==> insert x (xs ++ ys) == insert x xs ++ ys
            x <= y ==>     insert x (y:xs) == x:y:xs
             x < y ==>     insert y (x:xs) == x:insert y xs
ordered (ys ++ xs) ==>  sort ys ++ sort xs == sort (xs ++ ys)
     all (x <=) xs ==>     insert y (x:xs) == insert x (insert y xs)
     all (x <=) ys ==> insert x (xs ++ ys) == insert x xs ++ ys