anchor.diff:              (if (consp mcar)
                 (awhen (tree-transform-compile-r mcar trn)
                   (enqueue form '(consp (car e)))
  -                (enqueue form `(#'(lambda (e) (block nil (and ,@!))) (car e))))
  +                (enqueue form `(#'((e) (block nil (and ,@!))) (car e))))
                 (if (numberp mcar)
                   (enqueue form `(= (car e) ,mcar))
                   (enqueue form `(eq (car e) ',mcar))))))
  
positive.code:     (setq ,name
        (make-tree-transform :placeholders ,placeholders
                             :match ,match
  			   :conversion #'(lambda (&key ,@(cadr placeholders))
  					 ,conversion)))
      (tree-transform-compile ,name)))
  
  
negative.code:   (setf (tree-transform-clips trn) nil)
    (let ((form (tree-transform-compile-r (tree-transform-match trn) trn)))
      (setf (tree-transform-compiled-match trn)
        (eval (car (macroexpand `#'((e trn)
          (and
            ,@form))))))))
  
  