anchor.diff:  
   (defun find-class (symbol &optional (errorp t) environment)
     (when (null environment)
  -    (setf environment sicl-env:*global-environment*))
  -  (let ((class (sicl-env:find-class symbol environment)))
  +    (setf environment sicl-genv:*global-environment*))
  +  (let ((class (sicl-genv:find-class symbol environment)))
       (if (and (null class) errorp)
   	(error 'no-such-class symbol)
   	class)))
  
positive.code: (defun (setf symbol-function) (new-definition symbol)
    (declare (type function new-definition)
  	   (type symbol symbol))
    (setf (sicl-env:fdefinition symbol sicl-env:*global-environment*)
  	new-definition))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
negative.code: (defun (setf fdefinition) (new-definition function-name)
    (declare (type function-name function-name)
  	   (type function new-definition))
    (setf (sicl-genv:fdefinition function-name sicl-genv:*global-environment*)
  	new-definition))
    
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  