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 notable for its delicate handling of contract pricing involving risk; for instance, it describes life annuities as follows: 'we observe men and women twenty-five years old purchasing life annuities at a cost such that within eight years they will receive their initial investment back; and although they may outlive those eight years, it is more likely (probabilior) that they will live twice that amount. Consequently, the buyer has in his favour what happens more frequently and is more probable.'