(define (argue s)
  (if (empty? s)
      '()
      (sentence (opposite (first s))
		(argue (bf s)))))

(define (opposite w)
  (cond ((equal? w 'like) 'hate)
        ((equal? w 'hate) 'like)
        ((equal? w 'wonderful) 'terrible)
        ((equal? w 'terrible) 'wonderful)
        ((equal? w 'great) 'awful)
        ((equal? w 'awful) 'great)
        ((equal? w 'terrific) 'yucky)
        ((equal? w 'yucky) 'terrific)
        (else w) ))