More polish

doc/ref/chap-word-lang.md

@@ -218,7 +218,6 @@ list of all elements in `a`.
 When the variable substitution is **unquoted**, there's no difference between
 `[*]` and `[@]`:
 
-    $ IFS=x
     $ A=(1 2 3)
     $ printf '<%s>\n' ${A[*]}
     <1>
@@ -233,6 +232,7 @@ When the variable substitution is **unquoted**, there's no difference between
 When double-quoted, the `[*]` form joins the elements by the first character of
 `IFS`:
 
+    $ IFS=x
     $ printf '<%s>\n' "${A[*]}"
     <1x2x3>
 
@@ -309,9 +309,9 @@ There are test operators with colons, and without:
 case of a word list, e.g. generated by `$*` or `$@`, it tests whether there is
 at least one element.
 
-**With** the colon, the shell checks whether the value is **non-empty**.  In
-the case of a word list, the test is performed after joining the elements by a
-space.
+**With** the colon, the shell checks whether the value is **non-empty** (is not
+the empty string).  In the case of a word list, the test is performed after
+joining the elements by a space.
 
 Elements are joined by the first character of `IFS` only with double-quoted
 `"${*:-}"`.