ScalingStacks

Definition 3.3. A partition of a variety $X$ into subvarieties $X_{1},\dots,X_{n}$ (called strata) is an affine paving, if $X_{\leq k}=\bigcup_{i=1,\dots,k}X_{i}$ is closed in $X$ for all $1\leq l\leq n$ and each stratum $X_{i}$ is isomorphic to an affine space $\mathbb{A}^{n}.$