Monotonicity of the dimension-bounded classes #
Kollár's "dim X = n" in [Kol07, Lemma 102, Theorem 103 and Theorem 107] is read throughout the
library as "dim X ≤ n" (Triple.HasDimLE), so that disjoint unions and the restriction to a
component of the boundary stay in the class; the classes of the stage-n functors —
Triple.BOClass n m and MarkedTriple.BMOClass n m — therefore grow with the dimension bound: a
triple of dimension ≤ n' has dimension ≤ n for n' ≤ n. These three one-line inclusions place a
triple of the smaller class in the larger one; the coherence statements of
Hironaka.Resolution.Algebraic.Stage.Coherence and the restriction of the stage-n functor to the
stage-n' class (OrderSeqAssignment.restrict) use them.
The class BOClass n' m of [Kol07, Theorem 103] lies in BOClass n m for n' ≤ n.
The class BMOClass n' m of [Kol07, Theorem 107] lies in BMOClass n m for n' ≤ n.