How do I put vertical bars around multiple lines of maths?

Question

I have multiple lines in maths mode, and would like to contain all them in the same vertical lines - kind of like a box around multiple lines but without the top and bottom borders. I would like for this to work in both in-line maths mode ($...$) and the other maths mode ($$...$$, I don't know what its called).

For example, how would you put vertical lines around something like this:
$|a|\Rightarrow|b|$\\
$\text{....}\boxminus|a|\Rightarrow|b|$\\
$\text{....}\Leftrightarrow\neg|a|\vee|b|$\\

I have searched for solutions, and tried using the bars for determinants from linear algebra, but the formatting was very inconsistent with them.

Answer 1

I propose two easy way:

\documentclass[10pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx,framed}
\begin{document}
    \begin{leftbar}
        $|a|\Rightarrow|b|$\\
        $\text{....}\boxminus|a|\Rightarrow|b|$\\
        $\text{....}\Leftrightarrow\neg|a|\vee|b|$\\
    \end{leftbar}

\vspace{1cm}
\begin{tabular}{|l}
    $|a|\Rightarrow|b|$\\
    $\text{....}\boxminus|a|\Rightarrow|b|$\\
    $\text{....}\Leftrightarrow\neg|a|\vee|b|$\\
\end{tabular}
\end{document}

Output: