# The tex2jax Preprocessor¶

The options below control the operation of the tex2jax preprocessor that is run when you include "tex2jax.js" in the extensions array of your configuration. They are listed with their default values. To set any of these options, include a tex2jax section in your MathJax.Hub.Config() call. For example

MathJax.Hub.Config({
tex2jax: {
inlineMath: [ ['$','$'], ['\$$','\$$'] ]
}
});


would set the inlineMath delimiters for the tex2jax preprocessor.

inlineMath: [['$$','$$']]

Array of pairs of strings that are to be used as in-line math delimiters. The first in each pair is the initial delimiter and the second is the terminal delimiter. You can have as many pairs as you want. For example,

inlineMath: [ ['$','$'], ['\$$','\$$'] ]


would cause tex2jax to look for $...$ and $$...$$ as delimiters for inline mathematics. (Note that the single dollar signs are not enabled by default because they are used too frequently in normal text, so if you want to use them for math delimiters, you must specify them explicitly.)

Note that the delimiters can’t look like HTML tags (i.e., can’t include the less-than sign), as these would be turned into tags by the browser before MathJax has the chance to run. You can only include text, not tags, as your math delimiters.

displayMath: [ ['$$','$$'], ['$','$'] ]

Array of pairs of strings that are to be used as delimiters for displayed equations. The first in each pair is the initial delimiter and the second is the terminal delimiter. You can have as many pairs as you want.

Note that the delimiters can’t look like HTML tags (i.e., can’t include the less-than sign), as these would be turned into tags by the browser before MathJax has the chance to run. You can only include text, not tags, as your math delimiters.

processEscapes: false

When set to true, you may use \$ to represent a literal dollar sign, rather than using it as a math delimiter. When false, \$ will not be altered, and the dollar sign may be considered part of a math delimiter. Typically this is set to true if you enable the $...$ in-line delimiters, so you can type \\$ and tex2jax will convert it to a regular dollar sign in the rendered document.

processRefs: true

When set to true, MathJax will process \ref{...} outside of math mode.

processEnvironments: true

When true, tex2jax looks not only for the in-line and display math delimiters, but also for LaTeX environments (\begin{something}...\end{something}) and marks them for processing by MathJax. When false, LaTeX environments will not be processed outside of math mode.

preview: "TeX"

This controls whether tex2jax inserts MathJax_Preview spans to make a preview available, and what preview to use, when it locates in-line or display mathematics in the page. The default is "TeX", which means use the TeX code as the preview (which will be visible until it is processed by MathJax). Set to "none" to prevent previews from being inserted (the math will simply disappear until it is typeset). Set to an array containing the description of an HTML snippet in order to use the same preview for all equations on the page.

Examples:

preview: ["[math]"],     //  insert the text "[math]" as the preview

preview: [["img",{src: "/images/mypic.jpg"}]],  // insert an image as the preview


See the description of HTML snippets for details on how to represent HTML code in this way.

skipTags: ["script","noscript","style","textarea","pre","code"]

This array lists the names of the tags whose contents should not be processed by tex2jax (other than to look for ignore/process classes as listed below). You can add to (or remove from) this list to prevent MathJax from processing mathematics in specific contexts.

ignoreClass: "tex2jax_ignore"

This is the class name used to mark elements whose contents should not be processed by tex2jax (other than to look for the processClass pattern below). Note that this is a regular expression, and so you need to be sure to quote any regexp special characters. The pattern is inserted into one that requires your pattern to match a complete word, so setting ignoreClass: "class2" would cause it to match an element with class="class1 class2 class3" but not class="myclass2". Note that you can assign several classes by separating them by the vertical line character (|). For instance, with ignoreClass: "class1|class2" any element assigned a class of either class1 or class2 will be skipped.

processClass: "tex2jax_process"

This is the class name used to mark elements whose contents should be processed by tex2jax. This is used to restart processing within tags that have been marked as ignored via the ignoreClass or to cause a tag that appears in the skipTags list to be processed rather than skipped. Note that this is a regular expression, and so you need to be sure to quote any regexp special characters. The pattern is inserted into one that requires your pattern to match a complete word, so setting processClass: "class2" would cause it to match an element with class="class1 class2 class3" but not class="myclass2". Note that you can assign several classes by separating them by the vertical line character (|). For instance, with processClass: "class1|class2" any element assigned a class of either class1 or class2 will have its contents processed.