anchor.diff:  		   (null (cddr name))
   		   (eq (car name) 'setf)
   		   (symbolp (cadr name)))))
  -  (find name (function-entries environment)
  -	:test #'equal :key #'name))
  +  (gethash name (function-entries environment)))
   
   (defun ensure-function-entry (environment name)
     (let ((entry (find-function-entry environment name)))
  
positive.code:    ;; This slot holds a list of variable entries.
     (%variable-entries :initform '() :accessor variable-entries)
     ;; This slot holds a list of function entries.
     (%function-entries :initform '() :accessor function-entries)
     ;; This slot holds an association list, mapping function names to
     ;; compiler-macro functions.
     (%compiler-macro-expanders :initform '() :accessor compiler-macro-expanders)
  
negative.code:       (setf entry
  	    (make-instance 'function-entry
  	      :name name))
        (setf (gethash name (function-entries environment)) entry))
      entry))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  