anchor.diff:  ;;; simultaneously exist a global macro entry and a global function
   ;;; entry for the same name N.  However, in that case, the storage
   ;;; cell of the location of the global function entry always contains
  -;;; +unbound+.
  +;;; +funbound+.
   ;;;
   ;;; A global function entry can come into existence in several ways:
   ;;; 
  
positive.code: 	      ;; In this case, there can not also be a special
  	      ;; operator entry for the same name.
  	      (let ((value (car (storage (location function-entry)))))
  		(if (eq value  +unbound+)
  		    (error 'undefined-function :name function-name)
  		    value))
  	      ;; If we did not find a global function entry, see if
  
negative.code: ;;; remove it too.
  ;;;
  ;;; If there is a base entry and that entry is a global function
  ;;; entry, we just mark it as +funbound+, but we remove any auxiliary
  ;;; entry that refers to it in PROCLAMATIONS.  This means that if
  ;;; anyone uses FMAKUNBOUND with the intention of later giving the
  ;;; function a new definition, then they must again proclaim its type,
  