Tedious mathematical work on fast neutron calculations, relativity, complex hydrodynamics and quantum mechanics were conducted by the TPG led by Salam until 1974 when he left Pakistan in protest, though he kept close contact with TPG. No such endeavours of the kind had taken place in the country and computerized numerical control (CNC) and basic computing facilities were non-existent at that time (though later acquired). For this purpose, the calculations on the high-performance computing and numerical analysis were performed by Dr. Tufail Naseem, a PhD graduate in mathematics from Cambridge University, assisted by other members of Mathematics Division– the division of pure mathematics at PAEC under Dr. Raziuddin Siddiqui and Asghar Qadir. About the lack of CNC facilities, Munir Ahmad Khan famously marked: "If the Americans could do it without CNC machines in the 1940s, why can't we do the same now.". With Abdus Salam departing, Munir Ahmad eventually led the TPG and assisted in the calculations. Two types of weapon design were analyzed: the Gun-type fission weapon and the implosion nuclear weapon. The program turned to the more technically difficult implosion-type weapon design, contrary to the relatively simple 'gun-type' weapon.