anchor.diff:  
   (defclass graphics-state ()
     ((bindings)
  -   (program)
  +   (program :accessor program :initform :program)
      (uniform-sets)))
   
   ;;; Uniforms variables, as defined in OpenGL, are slowly-changing values
  
positive.code: (defclass renderer ()
    ((buffers :accessor buffers :initform nil)
     (bundles :accessor bundles :initform nil)
     (new-bundles :accessor new-bundles :initform nil)))
  
  ;;; A simple reference counting protocol for objects that should do some
  ;;; cleanup e.g., release OpenGL resources, when they are no longer used.
  
negative.code:   ((descriptor :accessor descriptor :initarg :descriptor)
     (local-storage :accessor local-storage)
     (strategy-data :accessor strategy-data)))
  
  
  (defun has-valid-strategy-p (uset)
    (with-slots (descriptor strategy-data)
  