orange U2G9PTIU orange “Theorem 1.1. [Kaw08, Theorem 1] Let (W, BW ) be a Q-factorial terminal pair, and (X, B), (Y, D) two minimal models of (W, BW ). Then the birational map X 99K Y may be factored as a sequence of (KX + B)-fl” (Wang 和 Chen, p. 1)