fix typo

Author: omahs

docs/codeql/ql-language-reference/expressions.rst

@@ -557,7 +557,7 @@ for a given ``f``.
 In this query, oranges are available at two different prices, and the
 default ``sum`` aggregate returns a single line where Alice buys an
 orange at a price of 100, another orange at a price of 1, and an apple
-at a price of 100, totalling 201. On the other hand, in the the
+at a price of 100, totalling 201. On the other hand, in the 
 *monotonic* semantics for ``sum``, Alice always buys one orange and
 one apple, and a line of output is produced for each *way* she can
 complete her shopping list.