anchor.diff:  ;; for unbound variables this encoding assumes that integers will not be used
   ;; as functors
   
  -;;(eval-when (eval compile load)
  +;;(eval-when (:compile-toplevel :load-toplevel :execute)
   ;;  (pushnew :include-name-in-variable *features*))
   
   (defun new-variable (var-name var-level)
  
positive.code: (defun wrap-call-fail-trace (form)
    (if traceable `(trace-call-fail ,name ,form) form))
  
  (eval-when (eval compile load)
    (defun wrap-exit-redo-trace (form)
      (if traceable `(trace-exit-redo ,name ,form) form)))
  
  
negative.code: 
  ;; SUPPORT FOR OUTPUT AND TRACING
  
  (eval-when (:compile-toplevel :load-toplevel :execute)
    (defmacro specifier (x)
      `(get ,x 'specifier))
    (defmacro precedence (x)
  