(def!macro cas (place old new &environment env)
"Synonym for COMPARE-AND-SWAP.
-Addtionally DEFUN, DEFGENERIC, DEFMETHOD, FLET, and LABELS can be also used to
+Additionally DEFUN, DEFGENERIC, DEFMETHOD, FLET, and LABELS can be also used to
define CAS-functions analogously to SETF-functions:
(defvar *foo* nil)