1 (defun dot-product (v w)
2   (accumulate #'+  0 (mapcar #'* v w)))
3 (defun matrix-*-vector (m v)
4   (mapcar
5    (lambda (row)
6      (dot-product row v))
7    m))
8 (defun transpose (m)
9   (accumulate-n #'cons nil m))
10 (defun matrix-*-matrix (m n)
11   (let ((n-t (transpose n)))
12     (mapcar (lambda (row)
13 	      (matrix-*-vector n-t row))
14 	    m)))