(define powerset
  (lambda(lista)
    (cond
      [(null? lista)'(())]
      [else (letrec
                (
                 (lista_sin1 (powerset (cdr lista)))
                 (organizar
                   (lambda (l)
                     (cond
                       [(null? l)'()]
                       [else(append(list(flatten(car l)))(organizar(cdr l)))])))
                 )
              (organizar(append (cartesian-product (list(car lista))lista_sin1)
                      lista_sin1)))])))

;;auxiliar flatten

(define flatten
  (lambda (l)
    (cond [(null? l) '()]
          [(list? l) (append (flatten (car l)) (flatten (cdr l)))]
          [else (list l)])))