deriving-instances.md

@@ -57,6 +57,6 @@ As there are only a few fixed methods/classes that can be derived, we may choose
 class Eq a where
   (==) :: a -> a -> Bool
   (/=) :: a -> a -> Bool
-  -- (==) has a magic way of be derived for datatypes 
+  -- (==) has a magic way of being derived for datatypes 
   x /= y = not (x == y)
 ```
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