+(defstruct (negation-type (:include ctype
+ (class-info (type-class-or-lose 'negation))
+ ;; FIXME: is this right? It's
+ ;; what they had before, anyway
+ (enumerable t)
+ (might-contain-other-types-p t))
+ (:copier nil)
+ #!+cmu (:pure nil))
+ (type (missing-arg) :type ctype))
+
+(!define-type-class negation)
+