Removed some extraneous and confusing parenthesized expressions.
Noted by Skip Montanaro <skip@mojam.com>.
diff --git a/Doc/ref/ref5.tex b/Doc/ref/ref5.tex
index 5bca8ed..1ef032b 100644
--- a/Doc/ref/ref5.tex
+++ b/Doc/ref/ref5.tex
@@ -840,15 +840,15 @@
expression_list: expression ("," expression)* [","]
\end{verbatim}
-An expression (expression) list containing at least one comma yields a
+An expression list containing at least one comma yields a
tuple. The length of the tuple is the number of expressions in the
list. The expressions are evaluated from left to right.
\obindex{tuple}
The trailing comma is required only to create a single tuple (a.k.a. a
\emph{singleton}); it is optional in all other cases. A single
-expression (expression) without a trailing comma doesn't create a
-tuple, but rather yields the value of that expression (expression).
+expression without a trailing comma doesn't create a
+tuple, but rather yields the value of that expression.
(To create an empty tuple, use an empty pair of parentheses:
\code{()}.)
\indexii{trailing}{comma}