In the paper **Representation type of the blocks of category $\mathcal{O}_S$ in types $F_4$
and $G_2$:**

Section 2.3, I quote " Assume from now on that $\mu$ is an integral weight and $\mu+\rho$ is antidominant; i.e., $(\mu+\rho,\alpha^\lor) \in \mathbb{Z}_{\le 0}$ for all $\alpha\in\Delta$; (if it is not antidominant, we can replace it by a W -translate, so we are justified in making this assumption). Let $\Phi_\mu = \{ \alpha\in\Phi: (\mu+\rho,\alpha^\lor)=0\}$.

If $\Phi_\mu = \emptyset$, then $\mu + \rho$ is a regular weight.

**If $\mu+\rho$ and $\nu+\rho$ are both regular weights, then $\mathcal{O}^\mu_S$ is equivalent to $\mathcal{O}^\nu_S$ by the Jantzen–Zuckerman translation principle.**"

I would like to know why the last assertion is true? What is Jantzen–Zuckerman translation principle?