anchor.diff:  
   BODY:           A list of forms.
   
  -RETURN:         Three values: a docstring or nil, a list of declarations, a list of forms.
  +RETURN:         Three values: a list containing one docstring or nil,
  +                a list of declarations, a list of forms.
   "
       (flet ((progn-body (body)
                (if (some (lambda (form) (and (consp form) (eq 'declare (first form))))
  
positive.code: NOTE:   This parses the body as a lambda body.
          It's better to use PARSE-BODY directly.
  "
      (values (parse-body :lambda body)))
  
  
    (defun extract-declarations (body &optional (allow-docstring t))
  
negative.code:            (handler-case
                 (multiple-value-bind (doc dec for) (parse-body :lambda body)
                   (assert (not expect-error-p))
                   (assert (equalp (first doc) docstring))
                   (assert (equalp dec declarations))
                   (assert (equalp for forms)))
               (program-error () (assert expect-error-p))))
  