Fixed typo in domain.rst.
@@ -1738,7 +1738,7 @@ concisely in the following way.
Non-trivial command methods
---------------------------
-Tn the examples above, the work of the command methods is "trivial", in
+In the examples above, the work of the command methods is "trivial", in
that the command method arguments are always used directly as the aggregate event
attribute values. But often a command method needs to do some work before
triggering an event. As a result of this processing, the event attributes
