- (type-union type1
- (apply #'type-intersection
- (remove (specifier-type '(not integer))
- (intersection-type-types type2)
- :test #'type=))))
+ (let* ((intersected (intersection-type-types type2))
+ (remaining (remove (specifier-type '(not integer))
+ intersected
+ :test #'type=)))
+ (and (not (equal intersected remaining))
+ (type-union type1 (apply #'type-intersection remaining)))))