anchor.diff:  	  (alexandria:symbolicate sketch '- (car binding)))))
   
   (defun make-slot-form (sketch binding)
  -  (let ((name (car binding))
  -	(accessor (binding-accessor sketch binding)))
  -    `(,name :initarg ,(alexandria:make-keyword name)
  -	    :accessor ,(binding-accessor sketch binding))))
  +  `(,(car binding) :initarg ,(alexandria:make-keyword (car binding))
  +     :accessor ,(binding-accessor sketch binding)))
   
    ;;; DEFSKETCH channels
  
positive.code: 
  ;;; Initialization
  
  (defmethod initialize-instance :after ((instance sketch) &rest initargs &key &allow-other-keys)
    (initialize-environment instance)
  
negative.code: 
  (defmacro defsketch (sketch-name bindings &body body)
    `(progn
       (defclass ,sketch-name (sketch)
         ,(sketch-bindings-to-slots `,sketch-name bindings))
  
       ,@(remove-if-not #'identity (make-channel-observers sketch-name bindings))
  
       (defmethod prepare progn ((instance ,sketch-name) &rest initargs &key &allow-other-keys)
         (let* (,@(window-parameter-bindings bindings)
  