Nested indentation of text blocks

Question

How can I doubly indent some lines of text?

The general idea is...

Normal
Once indented
Once indented
Twice indented 
Once indented
...

The following is my attempt but it only indents once.

  for each $v \in win$\\

\addtolength{\leftskip}{1cm}
if ($pl(v) = 1 \& \exists (v,v') \in E : v' \in win$)\\
{\addtolength{\leftskip}{1cm}$win \cup= v; st \cup = \{v \rightarrow v'\}$}\\
if ($pl(v) = 2 \& \forall (v,v') \in E : v' \in win$)\\
{\addtolength{\leftskip}{1cm}$wim \cup= v;$}\\
if ($pl(v) = 2 \& \exists (v,v') \in E : v' \in lose$)\\
{\addtolength{\leftskip}{1cm}$lose \cup=v$;}\\

Could someone please tell me a better way of doing this, and/or why my attempt doesn't work?

Many thanks.

Answer 1

I think what you're looking for is something like this.

\documentclass{article}
\begin{document}
\begin{tabbing}
\hskip\parindent\=\hskip\parindent\=\kill
For each $v\in win$,\+\\
if ($pl(v)=1\ \&\ \exists(v,v')\in E:v'\in win$)\\
\>$\mathit{win}\cup=v;st\cup=\{v\rightarrow v'\}$\\
if ($pl(v) = 2 \& \forall (v,v') \in E : v' \in win$)\\
\>$wim \cup= v;$\\
if ($pl(v) = 2 \& \exists (v,v') \in E : v' \in lose$)\\
\>$lose \cup=v$;\\
\end{tabbing}
\end{document}

In the interest of keeping the answer as close to your example as possible, I've kept the math exactly as you wrote it, but I don't think that's a good idea. Writing things like $win$ will typeset it as the multiplication of w, i, and n.

As an explanation,

• \= sets the tab stops. So here, I'm setting 2 tab stops: one at 1 \parindent and one 1 \parindent later.
• \kill ignores the previous text which is used just for setting the tab stops.
• \+ indents all following commands by one tab stop.
• \> moves to the next tab stop.

There are analogous \- and \< commands that do what you would expect. (There are also \' and \` which do strange things inside the tabbing environment, but I've never used them.)

Answer 2

I nest quote environments when I want to achieve such an effect:

Normal
  \begin{quote}
  Once indented
  Once indented
    \begin{quote}
    Twice indented 
    \end{quote}
  Once indented
  \end{quote}

You may also wish to define your own indentation environment where you can control left and right margins and vertical skips before and after. But that's a different question.

For example, you can define an environment indentmore this way (initially, I've borrowed changemargin from this page, thanks to Hendrik for converting it to LaTeX):

\newenvironment{changemargin}[2]{%
\list{}{\rightmargin#2\leftmargin#1
\parsep=0pt\topsep=0pt\partopsep=0pt}
\item[]}
{\endlist}

\newenvironment{indentmore}{\begin{changemargin}{1cm}{0cm}}{\end{changemargin}}

Change \parsep, \partopsep and \topsep to control vertical spacing).

This is how nested indentmore look like in text:

You can find the complete source of the example at pastebin.

Answer 3

The answer depends on what you want to achieve. Indentation usually means that only the first line of a paragraph is indented (by the \parindent amount). You increased \leftskip, which means that the whole paragraph gets an increased left margin.

Your attempt with \leftskip didn't work because you need to end the paragraph before ending the group with }. The following works:

{\addtolength{\leftskip}{1cm}This has an increased left margin.\par}

If you only want to indent the first line of a paragraph (or if you only have single lines anyway), then you can use

{\addtolength{\parindent}{1cm}This has an additional indentation of 1cm.}

(No need to end the paragraph here.)

Answer 4

The given text looks like an equation which could be aligned, hence \eqalign might be appropriate here (this is in plain-tex):

$$\eqalign{
{\rm for each\ } v \in win\cr
{\rm if\ } \big(pl(v) &= 1 \mathrel{\&} \exists (v,v') \in E : v' \in win\big)\cr
win \cup&= v; st \cup = \{v \to v'\}\cr
{\rm if\ } \big(pl(v) &= 2 \mathrel{\&} \forall (v,v') \in E : v' \in win\big)\cr
wim \cup&= v;\cr
{\rm if\ } \big(pl(v) &= 2 \mathrel{\&} \exists (v,v') \in E : v' \in lose\big)\cr
lose \cup&=v;\cr
}$$
\bye

Which yields:

Answer 5

\hspace{1cm} One indent \linebreak
\hspace{2cm} Two indent \linebreak

or

\indent One indent \linebreak
\indent \indent Two indent \linebreak

Though the latter is a bit sloppy.

Answer 6

The best solutions are normally the simpler. TeX defines a macro called narrower that simply makes a paragraph indent by one more parindent. Similarly we can define a macro called wider as shown in the minimal example below:

\documentclass[11pt]{article} 
\usepackage{lipsum}
\begin{document}
\parindent=1em
\lipsum[1]
\narrower
\lipsum[2]
\narrower\narrower
\lipsum[1]
\def\wider{%
 \advance\leftskip -\parindent
 \advance\rightskip -\parindent}
\wider\lipsum[1]
\wider\lipsum[1]
\wider\lipsum[1]
\end{document}

Should you not want the right side indentation you can remove the rightskip in both the definition of wider as well as narrower. A gentle reminder, is always best to elaborate your code with a full working minimal example.