[Tex/LaTex] Why gap + indent after \\ and [return]

indentationline-breakingparagraphs

I'm using TeXLive (pdftex) with TexShop on my Mac and usually, I don't format my .tex files. Now that I have to write some bigger ones, the code soon gets too messy to read and I tried to insert some newlines/returns to divide my code blocks. So why does my TeX package (or my TexShop) turn this into additional newlines and on top of that, indents?

For example, consider this minimum example:

\documentclass[10pt,a4paper,fleqn]{article}
\begin{document}
\section{Test}
\subsection{Sub1}
A line\\\\

newline
\end{document}

Why does this turn into (something like) this:

A Line



___newline

Is this some feature of TeX? I really want to format my code, can I turn this off somewhere?

edit (solved):

ok, as egreg said, I'm now using an empty line to end a paragraph. With this, my code gets a bit cleaner. But now, something like this:

\documentclass[10pt,a4paper,fleqn]{article}
\usepackage{amsthm}
\theoremstyle{definition}
\newtheorem{defi}{Definition}[section]
\begin{document}
\begin{defi}
....
\end{defi}

\begin{defi}
....
\end{defi}
\end{document}

(just as an example) compiled, these two theorems get (visually) really close to each other (less line spacing than between two \items of an itemize, even though I inserted a blank line there), which I think, does not look good. Why is this? Basically I am asking when to use \\, \\\\ and a blank line, now that you all shattered my beliefs ;D

edit 2: solved it myself, just removed \usepackage{parskip} and now it looks really nice. thank you all!

Best Answer

if you want a paragraph skip instead of the indentation then set:

\setlength\parindent{0pt}
\setlength\parskip{\medskipamount}

Related Solutions

[Tex/LaTex] Why is text being placed beyond the specified line width

The short answer to your main question is that TeX can never be forced to keep text within the margins; it only tries very hard to do so. As you have found out, it is fairly easy to cause it to fail.

The slightly longer answer is that TeX works by minimizing the total badness of a paragraph, where badness is computed by a variety of factors, such as stretching and shrinking of spaces to make the text fit, hyphenations, and so on. Beyond a certain badness, though (10000 to be precise), the paragraph is considered to be infinitely bad, and so TeX sort of gives up.

In Case 1a, due to the very long word and relative lack of stretchable space, TeX couldn't find a hyphenation point that produced an acceptable outcome, so the long word remained unhyphenated and going into the margin. In case 2a, there is much more white space to stretch, and perhaps also you were fortunate enough to have a hyphenation point within a suitable range.

As to minipages, LaTeX treats a minipage as if it were one humongous letter. That is why you need the blank line after it in order to start a new line there.

[Tex/LaTex] Occasional gap between paragraphs, no indent on first para

Using \noindent removes the indent (of length \parindent) from a single paragraph and requires manual usage at every paragraph. To void the paragraph indent altogether, use

\setlength{\parindent}{0pt}

in your document preamble, or at the start of your document (after \begin{document}).

If you're after an automated approach to have some paragraphs not indented after placing a \medskip, you should define your own \medskipnoindent macro (defined as \medskip\noindent) that does exactly that. Here's a minimal example showing this:

enter image description here

\documentclass{article}
\usepackage{lipsum}% http://ctan.org/pkg/lipsum
\newcommand{\medskipnoindent}{\medskip\noindent}%
\begin{document}
\section{A section}
\lipsum[1] \medskip
\lipsum[2] \medskipnoindent
\lipsum[3]
\end{document}

The above example has a standard inter-paragraph skip. If you want to remove this, you could use \setlength{\parskip}{0pt}. Regardless, for any \parskip or \parindent-related modifications, consider using the parskip package.

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