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: ;;; %% Miscellaneous Monadic Functions
  
  (labels ((defop-monadic (op &optional (classes %numeric-instance-classes%))
  	   (defop op :diadic-p nil :variadic-p nil
  		  :default nil :classes classes)))
  
  ;;; %%% EXP
  
  
negative.code: 
  ;; regarding reading of floating point values,
  ;; on a sidebar, see also SB-IMPL::MAKE-FLOAT
  
  (defun log10 (a)
    "Calculate the decimal logarithm of A"
    (declare (inline @log))
    (@log a 10))
  
  (defop 'log10 :diadic-p nil)
  
  (defun log-10 (a)
    "Calcluate the inverse decimal logarithm of A, 
  i.e 10 rasied to A degree"
    (declare (inline @expt))
    (@expt 10 a))
  
  (defop 'log-10 :diadic-p nil)
  