anchor.diff:  
   (defun defop (op &key 
                      (classes %numeric-instance-classes%)
  -                   (default (find-class 'number))
   		   (monadic-p t)
   		   (diadic-p t)
  -                   (variadic-p t))
  +                   (variadic-p diadic-p)
  +		   (default (when diadic-p
  +			      (find-class 'number))))
     (declare (type symbol op)
              (type (or class-designator null) default)
              (type cons classes)
  
positive.code: 
  ;; regarding reading of floating point values,
  ;; on a sidebar, see also SB-IMPL::MAKE-FLOAT
  
negative.code: 
  (defop 'log :variadic-p nil)
  
  ;;; % Overloading for Other Monadic Functions
  
  ;; FIXME : Observing the implementation of the respetive CL functions
  