anchor.diff:  
   (defun var* (var1 var2)
     (make-var (sym var1)
  -            (+ (pow var1) (pow var2))))
  +            (+ (pwr var1) (pwr var2))))
   
   (defun polyreduce (poly)
     ((tokenreduce term+ equal-order) poly))
  
positive.code: (defun coeff (term) (car term))
  (defun vars (term) (cdr term))
  (defun sym (var) (car var))
  (defun pow (var) (cdr var))
  
  (defun id (val) val)
  
  
negative.code:   ((token-simplify coeff) term))
  
  (defun var-simplify (variable)
    ((token-simplify pwr) variable))
  
  (defun token-simplify (attr)
    (lambda (token)
  