+(define-condition standard-pprint-dispatch-table-modified-error
+ (reference-condition error)
+ ((operation :initarg :operation
+ :reader standard-pprint-dispatch-table-modified-operation))
+ (:report (lambda (condition stream)
+ (format stream "~S would modify the standard pprint dispatch table."
+ (standard-pprint-dispatch-table-modified-operation
+ condition))))
+ (:default-initargs
+ :references `((:ansi-cl :glossary "standard pprint dispatch table"))))
+