Consider the following
\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
\begin{align}
X_{n}=\begin{cases}
X_{n}^{I}= t_{1}\nu_{1}^{n}+r_{1}\nu_{2}^{n}, \quad -N\leq n<-d, \\
X_{n}^{II}= t_{2}\nu_{1}^{n}+r_{2}\nu_{2}^{n}, \quad \ -d<n<-1, \\
X_{n}^{III}=t_{3}\nu_{1}^{n}+r_{3}\nu_{2}^{n}, \quad \quad 1<n<d, \\
X_{n}^{IV}=t_{4}\nu_{1}^{n}+r_{4}\nu_{2}^{n}, \quad \quad d<n\leq N, \\
\end{cases}
\end{align}
\end{document}
how can I make sure that the = sign in the left column is aligned as well as the inequalities on the right?
Best Answer
One option is to try the
array
environment instead of the cases one.