although there seems to be enough space between the second equation and the tag, the equation is not fully centered. is there a way to suppress this spacing behaviour so that the equation stays centered? i don't intend to align different equations but to center equations of different length when using a tag, provided that there would not be any overlapping.
\documentclass{scrartcl}
\usepackage{amsmath}
\usepackage{lipsum}
\begin{document}
\lipsum[1]
\begin{equation*}
h(z)=f(z)-\sum_{j=1}^m a_j(z-z_0)^{-j}
\end{equation*}
\begin{equation*}
h(z)=f(z)-\sum_{j=1}^m a_j(z-z_0)^{-j},\tag{$z\in D\setminus\{ z_0 \}$}
\end{equation*}
\lipsum[1]
\end{document}
align
environment, and then use the delimiter $\&$ for your desired alignment? – Raaja_is_at_topanswers.xyz Apr 10 '17 at 12:03