anchor.diff:  
   (defun compute-array-vector (m)
     (declare (type array m)
  -           (values (simple-array t (*))))
  +           (values (simple-array * (*))))
     (let* ((len (apply #'* (the cons (array-dimensions m))))
            (retv (make-array len :element-type (array-element-type m))))
       (dotimes (n len retv)
  
positive.code:          (retv (make-array (array-dimensions m)
                             :element-type (array-element-type m))))
      (declare (type array-dimension-designator n-rows n-cols)
               (type (simple-array t (*)) vector-form))
      (labels ((nth-element (mv row col)
                 (declare (type array-dimension-designator posn)
                          (type (simple-array t (*)) mv)
                          (values number))
                 (aref (aref mv row) col)))
  
  
negative.code: 
  (defun column (m j)
    (declare (type array-dimension-designator j)
             (type (array * (* *)) m)
             (values (array * (* 1))))
    (let* ((n-rows (array-dimension m 0))
           (reslt (make-array (list n-rows 1)
                              :element-type (array-element-type m))))
      (declare (type array-dimension-designator n-rows)
               (type (array * (* 1)) reslt))
      (dotimes (n n-rows reslt)
        (setf (aref reslt n 0) 
              (aref m n j))
  