to the shares of the sons a share and one-fifth, and multiply them by fifteen; it becomes sixty-three. You give to the first legatee eleven, and except from it one-fifth of the remainder of the third, [which is] two shares, nine remains with him. You give to the holder of the third twenty-one, and thirty-three remains, with eleven for each son. If the second bequest is of one-third of the remainder of the estate, you add one to the fifteen, then remove one-third of the sixteen—but it has no third, so multiply it by three; it becomes forty-eight. Remove one-third of it, thirty-two remains, which is the share. Take a share, and add five to it, then remove one-third of that on account of the bequest of one-third of the remainder; four-fifths remains. Add it to the shares of the heirs, and multiply it by forty-five; it becomes one hundred and seventy-one. From it, [the calculation] is sound.

Section: If he left four sons, and bequeathed to a man one-third of his estate minus the share of one of them, or bequeathed to him the completion of the third upon the share of one of them, he gets one-ninth. Its calculation is that you give to the legatee and a son one-third of the estate; its two-thirds remain for three sons, with two-ninths for each one. So you know that the son's share of the third is two-ninths, and one-ninth remains for the legatee. If he bequeathed to another one-fifth of what remains of the estate after the first bequest, you set aside one-third of the estate, then take a share from it, return it to the two-thirds, and give to the second legatee one-fifth of that. There remains from the estate one-third of it, one-fifth of it, and four-fifths of a share for the heirs. Eliminate four-fifths of a share with its equivalent; there remains for him one-third of it and one-fifth, equal to one-third and one-fifth. Half of the estate, therefore, is equal to three shares, and the entire estate is six for the two legatees and the sons, with one share for each. (Another way): The shares of the sons are four, which is the remainder of an estate whose fifth has gone, so add to it its fourth for the second legatee; it becomes five. Then add to the share of a son that which completes the third, which is another share; it becomes six. If you wish, you assumed the estate to be five shares and a completion,