\[ \newcommand{\d}{\mathrm{d}} \newcommand{\e}{\mathrm{e}} \newcommand{\i}{\mathrm{i}} \]

Let \(\alpha, \beta \in \mathbb{N}^n\) multi-indices. Then

\begin{equation*} \alpha\pm \beta=(\alpha_1\pm \beta_1,\ldots,\alpha_n\pm \beta_n). \end{equation*}