It is especially notable for its subtle treatment of the pricing of contracts involving risks; for example it writes of life annuities, 'we see men and women twenty-five years old buying life annuities for a price such that within eight years they will receive their stake back; and although they may live less than those eight years, it is more probable (probabilius) that they will live twice that. Thus the buyer has in his favour what happens more frequently and is more probable.'
It is especially noteworthy for its careful consideration of contract pricing involving uncertainty; for instance, it explains the concept of life annuities by stating: 'we observe individuals twenty-five years old purchasing life annuities at a price that guarantees they will receive their initial investment back within eight years; and although they may outlive those eight years, it is more probable (probabilior) that they will live twice that amount. As a result, the buyer has in his favour what happens more frequently and is more probable.'