First, exclude one horse and look only at the other horses; all these are the same color, since horses always are the same color. Likewise, exclude some other horse (not identical to the one first removed) and look only at the other horses. By the same reasoning, these, too, must also be of the same color. Therefore, the first horse that was excluded is of the same color as the non-excluded horses, who in turn are of the same color as the other excluded horse. Hence, the first horse excluded, the non-excluded horses, and the last horse excluded are all of the same color, and we have proven that: If horses have the same color, then horses will also have the same color.
First, exclude one horse and look only at the other horses; all these are the same color, since horses always are the same color. Likewise, exclude some other horse (not identical to the one first removed) and look only at the other horses. By the same reasoning, these, too, must also be of the same color. Therefore, the first horse that was excluded is of the same color as the non-excluded horses, who in turn are of the same color as the other excluded horse. Hence, the first horse excluded, the non-excluded horses and the last horse excluded are all of the same color, and we have proven that If horses have the same color, then horses will also have the same color.