Fixed minor error.

user_guide/source/tutorial/ownership4.rst

@@ -43,7 +43,7 @@ If ownership is no longer desired, ``disown`` can be used to discard ownership.
        }
    }
 
-*IMPORTANT*: `disown` is should be used *only* when you really want to throw something out. Above, `disown` is required because of the manual arithmetic used to manipulate `amount` inside the implementation of `Money`, but it is *not* needed in most normal code.
+*IMPORTANT*: `disown` should be used *only* when you really want to throw something out. Above, `disown` is required because of the manual arithmetic used to manipulate `amount` inside the implementation of `Money`, but it is *not* needed in most normal code.
 
 Invoking transactions
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