A merge of two topics may not textually conflict but still have
conflict at the semantic level. A classic example is for one topic
-to rename an variable and all its uses, while another topic adds a
+to rename a variable and all its uses, while another topic adds a
new use of the variable under its old name. When these two topics
are merged together, the reference to the variable newly added by
the latter topic will still use the old name in the result.