[Tex/LaTex] What library do I have to use such that the document can render \lt and \gt as less than and greater than signs, respectively

math-modepackages

\documentclass{article}
%\usepackage{amsmath} It does Not work !
\begin{document}
\[
x\lt y \gt z
\]
\end{document}

What library do I have to use such that the document can render \lt and \gt as less than and greater than signs, respectively?

Edit

I am using MathJax library in my site under Asp.net Mvc 3. Web application is vulnerable to XSS and XSRF attacks so < and > should be avoided as the input from the users.

My database will save LaTeX commands that can be rendered by both LaTeX compiler and MathJax. Therefore, I need \gt and \lt that already work in MathJax.

Source:

enter image description here

Rendered:

enter image description here

Best Answer

If that's all you want, add

\newcommand{\lt}{<}
\newcommand{\gt}{>}

to the preamble (before begin{document}). This should allow you to use \ltand \gt.

Related Solutions

[Tex/LaTex] What do the pieces of LaTeX, \left and \right, respectively mean

\left and \right are used for delimiters when they have to change the size dynamically depending on the content. Consider the following example:

\documentclass{article}
\usepackage{amsmath}


\begin{document}
Compare this:
 \begin{align*}
 \left(\sqrt{2}+\sqrt{3}\right)^2
            &=\left(\sqrt{2}\right)^2+2\times\sqrt{2}\times\sqrt{
                3}+\left(\sqrt{3}\right)^2\\
            &=2+2\sqrt{6}+3\\
            &=5+2\sqrt{6}
\end{align*}
with:
\begin{align*}
 (\sqrt{2}+\sqrt{3})^2
            &=(\sqrt{2})^2+2\times\sqrt{2}\times\sqrt{
                3}+(\sqrt{3})^2\\
            &=2+2\sqrt{6}+3\\
            &=5+2\sqrt{6}
\end{align*}
First one uses \verb|\left(| and \verb|\right)| and second one uses just \verb|(| and \verb|)|. I hope the difference is clear. 

Just another example:    
\[\left(\frac{1}{2}\right) \qquad (\frac{1}{2})\]

\end{document}

enter image description here

In this particular case, the (\sqrt{2}+\sqrt{3}) with \left and \right gives bit bigger parenthesis making it to look ugly (to some extent) as noted by Enrico. In such cases, proper variant of delimiters (\bigl and \bigr in this case) may be used to get the appropriate height.

For more details, refer to amsmath documentation - page 15, section 4.14 (texdoc amsldoc from command prompt). Here is a screen shot of the same:

enter image description here

[Tex/LaTex] the cleanest way to redefine math-mode font commands such as \mathrm and \mathit to use a different font

Just redefine the macros \mathrm and \mathit to use a different font: the interface is

\DeclareMathAlphabet{<encoding>}{<family>}{<series>}{<shape>}

You can also supplement the font for a different math version: say also

\SetMathAlphabet{bold}{<encoding>}{<family>}{<series>}{<shape>}

for defining the font to be used in a \boldmath (or \mathversion{bold}) context.

An example follows. But beware that using Charter for \mathrm and \mathit is a typographical nonsense. Here's the visual proof of my claim.

\documentclass{article}
\usepackage{mathptmx}
\DeclareMathAlphabet{\mathrm}{OT1}{bch}{m}{n}
\DeclareMathAlphabet{\mathit}{OT1}{bch}{m}{it}

\begin{document}

Some text.

Some formula: \(abc = de/f \quad[\mathrm{var}, \mathit{val}]\)

Some formula: \(\mathit{abc}=\mathit{de}/\mathit{f}\)

\end{document}

enter image description here

Instead of \DeclareMathAlphabet one can define a substitute that won't eat up math families:

 \usepackage{amsmath}
 \newcommand{\mathcharter}[1][\encodingdefault]{%
   \text{\usefont{#1}{bch}{m}{n}#2}%
 }

and use it as

\mathcharter{abc}

or even

\mathcharter[T1]{l'Hôpital}

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Best Answer

Related Solutions

[Tex/LaTex] What do the pieces of LaTeX, \left and \right, respectively mean

[Tex/LaTex] the cleanest way to redefine math-mode font commands such as \mathrm and \mathit to use a different font

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