How to make a new line without indenting?

Question

How can I make a new line without it being indented? Here is what I have so far:

\documentclass[11pt, oneside, reqno]{article}
\usepackage{amssymb, amsthm, amsmath, amsfonts}
\usepackage{bardmacros}

\begin{document}

\demo

However, since $y \notin B$, we have $\mathbb{X\restriction_B} = 0$.  This is a contradiction, because $1 \neq 0$.  Therefore, $A=B$ must be true for $\mathbb{X\restriction_A} = \mathbb{X\restriction_B}$.\\\

$\Rightarrow$  Let $\mathbb{X\restriction_A} \neq \mathbb{X\restriction_B}$ and let $A=B$.
\edemo
\end{document}

And this is what the output looks like. The indent right before the => is what I'd like to eliminate:

I am very new the LaTeX, so thanks for your patience!

Answer 1

Why not use \\. This will initiate a new line without starting a new paragraph. If you are inside an environment you can also use \newline. To start a new paragraph you would use \par. \noindent should only be used when the paragraph does not directly follow another paragraph but something else such as a table or a section head (most styles do this automatically).