(expand 8)

; lcm expects two input expressions.  Both should be positive integers.  Lcm
; return the least common multiple of its two arguements.

(defun lcm (m n) (* (/ m (gcd m n)) n))

;  Greatest common divisor in iterative form.

(defun gcd (m n)
        (cond   ((and (equal 0 m) (equal 0 n)) 1)
                ((equal 0 m) n)
                ((equal 0 n) m)
                (t (gcd2 (abs m) (abs n)))
        )
)
;  Does work of gcd.  Gcd2 should not be called by any function except
;  gcd.
(defun gcd2 (m n)
        (progn  (setq m1 m)
                (setq n1 n)
                (while (not (equal m1 n1))
                    (cond ((< m1 n1) (setq dif (- n1 m1)))
                          (t  (setq dif (- m1 n1))))
                    (cond ((< m1 n1) (setq n1 m1)))
                    (setq m1 dif)
                )
                m1)
)