           fields)))
      (error "duplicate field name" ))
  (really-make-condition-type name
                              supertype
                              fields
                              (append (condition-type-all-fields supertype)
                                      fields)))

(define-syntax define-condition-type
  (syntax-rules ()
    ((define-condition-type ?name ?supertype ?predicate
       (?field1 ?accessor1) ...)
     (begin
       (define ?name
         (make-condition-type '?name
