f 1 = -1
f (-1) = 1
f (-2) = 2
f (-3) = 3

data Z a = Higher a a
         | Same a a
         | Lower a a

infixr 7 `Higher`

infixr 6 `Same`

infixr 5 `Lower`

g :: Z Int -> ()
g (-1 `Higher` x) = ()
g (-2 `Same` x) = ()
g (-3 `Lower` x) = ()