¹ One of the principles involved in logical deduction is to necessarily suppose something which renders all other alternatives impossible. The classical textbook example in traditional logic is: A mountain is on fire because though the fire cannot be seen, smoke is seen moving up towards the sky. In this argument, it is axiomatically accepted that smoke is necessarily seen only when there is fire and that there is no alternative cause of smoke. Similarly, a necessary supposition that renders all other alternatives impossible is found in the case of these two logical deductions: (1) Caitra, who is known to be alive, is not at home; therefore, Caitra is outside, and (2) The fat Devadatta does not eat during the day; therefore Devadatta eats at night. Lord Rāma, as a dhārmika warrior, had no alternative to kill Khara other than by slightly retreating back. That is the point made in this portion of the commentary.