[Tex/LaTex] Only left brace or bar in math equations

bracesequationsmath-mode

I wanna insert only a left bar like \left | without the closing right bar.

Why?
I want to use it as separator of calculation hints.

$a * b = c | :b\\ a = \frac{c}{b}$

and so on.

It must be a left bar and not only | or \vert so that it is scaled in height.

Best Answer

A single . can be used as the partner of a bracket, e.g.:

\left| \frac{b}{c} \right.
\left. \frac{b}{c} \right|

There is also \middle in order to scale something in the middle of an expression, e.g.:

\left. a * b = c \middle| :b \right.

However, in your case, probably you should use some way to align your computation across several lines. This can be done using, for example, the environment align from package amsmath:

\begin{align}
    a * b &= c   &&| :b\\
    a     &= \frac{c}{b}
\end{align}

This will, however, lead to the problem that you cannot use \left and \right across different cells of an align, as explained at https://tex.stackexchange.com/a/89621/88939.

Related Solutions

[Tex/LaTex] Using a big brace over multiple lines – multiple lines left of it

The mathtools package provides an environment called rcases; it behaves pretty much like the cases environment of the amsmath package does except that the curly brace is set at the right-hand end.

The following code uses both an rcases and an array environment:

enter image description here

\documentclass{article}
\usepackage{mathtools} % mathtools loads the amsmath package automatically
\begin{document}
\[
\begin{rcases}
H_0: & \theta =\theta_0 \in \Theta_0\\
H_1: & \theta =\theta_1 \in \Theta_1 
\end{rcases}
\quad
\begin{array}{r@{\;}l} % make space to RHS of \in and = symbols equal to that used for mathrel items
 \theta \in &\Theta  \\
 \Theta_0 \cup \Theta_1 = &\Theta \\
 \Theta_0 \cap \Theta_1 = &\emptyset
\end{array}
\]
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Using a big brace over multiple lines – multiple lines left of it

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