Before revision:  In our model the bond holders receive the  coupon at predetermined coupon dates and the face value (debt) and the coupon at the maturity as well as the effect of government taxes which are paid on the proceeds of an investment in bonds is considered .
After revision:  Here we consider the one factor model and the two factor model. In the one factor model the bond holders receive the coupon at predetermined coupon dates and the face value (debt) and the coupon at the maturity as well as the effect of government taxes which are paid on the proceeds of an investment in bonds is considered .