(when (and displaced-index-offset (null displaced-to))
(error "can't specify :DISPLACED-INDEX-OFFSET without :DISPLACED-TO"))
(if (and simple (= array-rank 1))
(when (and displaced-index-offset (null displaced-to))
(error "can't specify :DISPLACED-INDEX-OFFSET without :DISPLACED-TO"))
(if (and simple (= array-rank 1))