anchor.diff:                                    :normalization-factor normalization-factor
                                     :clip clip
                                     :do-matrix (do-matrix-macro-name matrix)))))
  +         (adder (compile nil
  +                         (eval
  +                          (list 'add-sv-to-approximation
  +                                :matrix matrix :clip clip
  +                                :do-matrix (do-matrix-macro-name matrix)))))
            (clip (coerce clip 'function)))
       (map-matrix
        (lambda (row column value i)
  
positive.code:     `(let* ((,%matrix ,matrix)
              (,dense-index 0)
              (,width (the fixnum (width-of ,%matrix))))
         (dotimes (,row (the fixnum (height-of ,%matrix)))
           (dotimes (,column ,width)
             (let ((,value (aref ,%matrix ,row ,column)))
  
negative.code:                             :clip clip :matrix matrix
                              :approximation approximation))
             (add (sv)
               (funcall adder sv approximation)))
        (loop for sv across svd do
              (add sv))
        (loop for n upfrom (length svd) do
  