Calculation of book profit for mat

As per AS-29, Provision should be made for Present obligations and when there is a reason to believe that there is probable outflow of economic resources which can be estimated reliably. i.e it means Ascertianed liability. While calculating MAT, Provision for  Ascertained liablities can be deducted hence no problem what ever the nomenclature may be. no problem whether it  is Provision for baddebts or provision for Doubtful debts if it is Ascertained liablity as per AS-9