Inserting new line under \exists in math mode [duplicate]

Question

Possible Duplicate:
Separate long math text under sum symbol into different lines?

Minimal example of my document. I'm using redesigned exists.

\documentclass{article}
\usepackage{amsfonts}
\usepackage{amsmath}

\let\stdexists\exists
\renewcommand{\exists}{\mathop{\vphantom{\sum}\mathchoice
  {\vcenter{\hbox{\huge$\stdexists$}}}
  {\vcenter{\hbox{\Large$\stdexists$}}}{\stdexists}{\stdexists}}\displaylimits}

\begin{document}
\begin{equation}
\exists_{j\in S j\neq i}\exists_{n \in \mathbb{N}} {p_{ij}}^{(n)}>0
\end{equation}
\end{document}

This code gives an output:

What I need is:

How can I do that?

Answer 1

Use the \substack command from the amsmath package.

\documentclass{article}
\usepackage{amsfonts}
\usepackage{amsmath}

\let\stdexists\exists
\renewcommand{\exists}{\mathop{\vphantom{\sum}\mathchoice
  {\vcenter{\hbox{\huge$\stdexists$}}}
  {\vcenter{\hbox{\Large$\stdexists$}}}{\stdexists}{\stdexists}}\displaylimits}

\begin{document}
\begin{equation}
\exists_{\substack{j\in S \\ j\neq i}}\exists_{n \in \mathbb{N}} {p_{ij}}^{(n)}>0
\end{equation}
\end{document}