vertical component

LEMMA 4.3 Assume Theorem 1.2n 1. Let .X; / be a divisorially log terminal pair where X is a Q-factorial projective variety of dimension n. Let A be an ample divisor such that KX C A C is pseudoeffective, and let W X Z be the ample model of KX C A C . Assume that no component of N D N.X; KX C A C / is a component of . If the dimension of Z is greater than the complexity of .X; /, then we may find a component P of which is vertical. (page) (Brown et al., 2018, p. 951)