+(defun maybe-distribute-one-union (union-type types)
+ (let* ((intersection (apply #'type-intersection types))
+ (union (mapcar (lambda (x) (type-intersection x intersection))
+ (union-type-types union-type))))
+ (if (notany (lambda (x) (or (hairy-type-p x)
+ (intersection-type-p x)))
+ union)
+ union
+ nil)))
+