anchor.diff:              ((tokenreduce reduce-fun equal-fun)
                (filter (equal-fun not (car tokens)) (cdr tokens))))
         nil)))
  +
  +(defun equal-order (fun term)
  +  ((equal-token vars) fun term))
  +
  +(defun equal-sym (fun var)
  +  ((equal-token sym) fun var))
   
   (defun equal-token (attr)
     (lambda (fun token1)
  
positive.code: (defun varreduce (variables)
    ((tokenreduce var* equal-sym) variables))
  
  (defun equal-order (fun term)
    ((equal-token vars) fun term))
  
  (defun equal-sym (fun var)
    ((equal-token sym) fun var))
  
  (defun tokenreduce (reduce-fun equal-fun)
    (lambda (tokens)
      (if tokens
  
negative.code:                   (termlist* poly1 (cdr poly2)))
      nil))
  
  (defun varlist* (vars1 vars2)
    (varreduce (append vars1 vars2)))
  
  