peg.texi: Fix bug#76555 even a bit more

* doc/lispref/peg.texi (Parsing Expression Grammars):
Fix other part of the grammar of `define-peg-ruleset` example.

(cherry picked from commit ba409f37125a4cf8b99718f9252f7804229663a2)

diff --git a/doc/lispref/peg.texi b/doc/lispref/peg.texi
index 193a7ca957e1a8f188dddfe6ec30128a4be11c45..d93b1f6df2996aff8a6ff3e2cdceffdd415609fb 100644 (file)
--- a/doc/lispref/peg.texi
+++ b/doc/lispref/peg.texi
@@ -142,8 +142,8 @@ Define @var{name} as an identifier for @var{rules}.
 @group
 (define-peg-ruleset number-grammar
   ;; `digit' here references the definition above.
-  (number sign digit (* digit))
-  (sign (or "+" "-" "")))
+  (number () sign digit (* digit))
+  (sign () (or "+" "-" "")))
 @end group
 @end example