@@ -124,6 +124,13 @@ instance Ord String where
124124 GT
125125
126126
127+instance Ord Bool where
128+ compare True True = EQ
129+ compare False False = EQ
130+ compare False True = LT
131+ compare True False = GT
132+
133+
127134instance (Ord a, Ord b) => Ord (a, b) where
128135 compare (xl, xr) (yl, yr) =
129136 if xl /= yl