(ad-special-form-p): Don't use `iff' in docstring.

diff --git a/lisp/emacs-lisp/advice.el b/lisp/emacs-lisp/advice.el
index 6c1f7be5c93028b64c7ba121f4b0f86cc8780c5e..b4dcd24597a39ed3ca92e97a2cf39d6501ddceed 100644 (file)
--- a/lisp/emacs-lisp/advice.el
+++ b/lisp/emacs-lisp/advice.el
@@ -2469,7 +2469,7 @@ will clear the cache."
   `(cdr ,definition))
 
 (defun ad-special-form-p (definition)
-  "Non-nil iff DEFINITION is a special form."
+  "Non-nil if and only if DEFINITION is a special form."
   (if (and (symbolp definition) (fboundp definition))
       (setq definition (indirect-function definition)))
   (and (subrp definition) (eq (cdr (subr-arity definition)) 'unevalled)))