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xTras:  a field theory inspired xAct package for Mathematica

Author: Teake Nutma © 2012-2013 under GPL.
Article: arXiv:1308.3493 [cs.SC]

Online documentationRelease historySource code


xTras is a field-theory inspired add-on package for xAct. Some of the extra functionality it brings is:

For more information, have a look at the online documentation or at the paper.

Latest release: xTras version 1.4.2 (2014-10-30)

What's new:

The full release history can be found here.


xTras is not a stand-alone package. It depends on various packages contained in the main xAct bundle. In order to install xTras, do the following:

The premier support channel is the main xAct mailing list. If you find a bug, you can also report it over at xTras' Github issue tracker.


Q: FullSimplification doesn't work and returns the RInv::nodatabase message. What's wrong?
A: FullSimplification needs the Invar database to work. Install it from and the message should go away.

Q: I don't see any built-in documentation in Mathematica, nor does the xTrasHelp[] command work.
A: xTras only got built-in documentation from version 1.2 onwards. Installing the latest version should fix this.