Integral lookup and CLISP

The defprop macro quotes the lambda expression, 
but this works:


;; Integral of the Bessel function wrt z 
(putprop '%bessel_j
  `((n z)
   nil
  ,(lambda (n unused)
    (case n
          (0
           ;; integrate(bessel_j(0,z) 
           ;; = (1/2)*z*(%pi*bessel_j(1,z)*hstruve[0](z) 
           ;;            +bessel_j(0,z)*(2-%pi*hstruve[1](z))) 
           '((mtimes) ((rat) 1 2) z
             ((mplus)
              ((mtimes) $%pi ((%bessel_j) 1 z)
               ((mqapply) (($hstruve array) 0) z))
              ((mtimes) ((%bessel_j) 0 z)
               ((mplus) 2 ((mtimes) -1 $%pi
                           ((mqapply) (($hstruve array) 1) z)))))))
          (1
           ;; integrate(bessel_j(1,z) = -bessel_j(0,z) 
           '((mtimes) -1 ((%bessel_j) 0 z)))
          (otherwise nil))))
  'integral)