anchor.diff:      '(%set-atom-fun cpr rplacp %load atan2 pow quit string-concat %load
         %eval %defun early-defun %defvar %defmacro %string %make-symbol
         %symbol-name %symbol-value %symbol-function %symbol-package
  -      %number?
  +      %number? ==
         ? functional
         builtin? macro?
         %%macroexpand %%macrocall %%%macro?
  
positive.code:       (number- -)
        (integer- -)
        (character- -)
        (== =)
        (number== =)
        (integer== =)
        (character== =)
  
negative.code:   (or (numberp x)
        (characterp x)))
  
  (defun == (a b)
    (= (? (characterp a)
          (char-code a)
          a)
       (? (characterp b)
          (char-code b)
          b)))
  
  (defun %%macroexpand (x)
    (? *macroexpand-hook*
        (funcall *macroexpand-hook* x)
  