@@ -31,7 +31,7 @@ data Picture = Picture
3131 , picBackground :: Background
3232 -- ^ The picture's background to be displayed in locations with no
3333 -- Image data.
34− }
34+ } deriving Eq
3535
3636instance Show Picture where
3737 show (Picture _ layers _ ) = "Picture ?? " ++ show layers ++ " ??"
@@ -109,6 +109,7 @@ data Background
109109 --
110110 -- * End of line if there are no remaining non-skip ops.
111111 | ClearBackground
112+ deriving Eq
112113
113114instance NFData Background where
114115 rnf (Background c a) = c `seq` a `seq` ()