+(defun contains-unknown-type-p (ctype)
+ (cond ((unknown-type-p ctype) t)
+ ((intersection-type-p ctype)
+ (some #'contains-unknown-type-p (intersection-type-types ctype)))
+ ((union-type-p ctype)
+ (some #'contains-unknown-type-p (union-type-types ctype)))))
+