We define four attributes on the bonds set--MATAT, PRICE, CAMNT, and BUY. MATAT stores the bonds' maturities, PRICE the price, CAMNT the coupon amount, and BUY the number of each bond to buy.

The NEED and SINVEST attributes are defined on the PERIOD set. NEED stores the cash needs in each period and SINVEST stores the amount in short-term investments in each period.