He was thinking by himself, and even seriously racking his brain to find a direction for this single force four times multiplied, with which he did not doubt, as with the lever for which Archimedes sought, they should succeed in moving the world, when someone tapped gently at his door.
El sí, él lo pensaba, y seriamente incluso, estrujándose el cerebro para encontrar dirección a aquella fuerza única multiplicada por cuatro, con la que no dudaba que, como con la palanca que buscaba Arquímedes, se podía levantar el mundo, cuando llamaron suavemente a la puerta.