test parentheses documentation improvement

I noticed that the texinfo documentation for 'test' did not mention
parentheses.  Here is a small patch to improve the documentation in
that area.

Bob

diff -ru ../fileutils-4.1.8.original/doc/coreutils.texi ./doc/coreutils.texi
--- ../fileutils-4.1.8.original/doc/coreutils.texi	Sat Mar 30 00:13:00 2002
+++ ./doc/coreutils.texi	Sat Apr  6 16:43:24 2002
@@ -8188,7 +8188,7 @@
 * File characteristic tests::   -e -s -nt -ot -ef
 * String tests::                -z -n = !=
 * Numeric tests::               -eq -ne -lt -le -gt -ge
-* Connectives for test::        ! -a -o
+* Connectives for test::        ! -a -o ()
 @end menu
 
 
@@ -8428,6 +8428,11 @@
 
 @table @samp
 
+@item ( @var{expr1} )
+@opindex ()
+@cindex ( expression )
+True if the grouped expression is true.
+
 @item ! @var{expr}
 @opindex !
 True if @var{expr} is false.
@@ -8445,6 +8450,11 @@
 True if either @var{expr1} or @var{expr2} is true.
 
 @end table
+
+@cindex parentheses for grouping
+Parentheses may be used for expression grouping.  However, since they
+are special to the shell you must quote parentheses to protect them from
+shell evaluation.
 
 
 @node expr invocation