sicp-ex-2.87

  
 ;; add into polynomial package 
 (define (zero-poly? poly) 
   (define (zero-terms? termlist) 
     (or (empty-termlist? termlist) 
         (and (=zero? (coeff (first-term termlist))) 
              (zero-terms? (rest-terms termlist))))) 
   (zero-terms? (term-list poly)))