setf in defmethod?

[Rick.Busdiecker@h.cs.cmu.edu]

I was under the impression that DefMeth and DefMethod were supposed to
have the same syntax for defining SetF methods, and that syntax was:

(DEFMETHOD (accessor-name (:SETF new-value)) defmethod-lambda-list
  body-of-setf-method)

While that syntax works fine for DefMeth, it fails under CMU CommonLisp
using the PCL of 1/26/87 with an error of the form:

Error in function STRING.
(accessor-name (:SETF (new-value))) cannot be coerced to a string.

What is the correct syntax for defining SetF methods using Defmethod?