;;; the proven type and the corresponding type in TYPES. If so, we opt
;;; for a :HAIRY check with that test negated. Otherwise, we try to do
;;; a simple test, and if that is impossible, we do a hairy test with
;;; the proven type and the corresponding type in TYPES. If so, we opt
;;; for a :HAIRY check with that test negated. Otherwise, we try to do
;;; a simple test, and if that is impossible, we do a hairy test with