Dimension–codimension formula for affine Deligne–Lusztig varieties

Let $G$ be the group under consideration, let $x\in\widetilde{W}$ be an element of its affine Weyl group, and let $b\in G$. Let $I$ be an Iwahori subgroup, let $X_x(b)$ be the associated affine Deligne–Lusztig variety, let $\ell(x)$ denote the length of $x$, let $\rho$ be the half-sum of the positive roots, and let $\overline{\nu}(b)$ be the Newton slope sequence associated to $b$. Dimension–codimension conjecture. The relationship between the dimension of $X_x(b)$ and the codimension of the associated set of Newton strata is

$$\dim X_x(b)+\operatorname{codim}\bigl((IxI)_{\leq\overline{\nu}(b)}\subseteq IxI\bigr)=\ell(x)-\langle 2\rho,\overline{\nu}(b)\rangle.$$

This proposes a precise relation between affine Deligne–Lusztig varieties and Newton strata in the Iwahori case; the source gives no resolution status.