sicp-ex-2.97

meteorgan
  
  
 ;;a 
 (define (reduce-terms n d) 
   (let ((gcdterms (gcd-terms n d))) 
         (list (car (div-terms n gcdterms)) 
               (car (div-terms d gcdterms))))) 
  
 (define (reduce-poly p1 p2) 
   (if (same-variable? (variable p1) (variable p2)) 
     (let ((result (reduce-terms (term-list p1) (term-list p2)))) 
       (list (make-poly (variable p1) (car result)) 
             (make-poly (variable p1) (cadr result)))) 
     (error "not the same variable--REDUCE-POLY" (list p1 p2)))) 
  
 ;;b. skip this, I had done such work many times, I'm tired of it.