EqOrd

EqOrd.hs

instance Eq Fraction where
  (/=) f    = not . (==) f
  (==) f f' = (x == x') && (y == y')
      where (Frac x y) = simplify f
            (Frac x' y') = simplify f'
  
instance Ord Fraction where
  compare (Frac a b) (Frac c d) = compare (a `quot` b) (c `quot` d)
  (<)  f    = (==) LT . compare f
  (>)  f    = (==) GT . compare f
  (>=) f    = not . (<) f
  (<=) f    = not . (>) f
  max  f f' = if f < f' then f' else f
  min  f f' = if f < f' then f else f'