Load the package

This loads the package from the default directory $HOME/.Mathematica/Applications/xAct for a single-user implementation under Linux, or from /user/local/Wolfram/Mathematica/5.2/AddOns/Applications/xAct for a system-wide installation. For installation under Windows or Mac see the Installation Notes.

In[1]:=

Out[1]=

In[2]:=

<<xAct`xPerm`

Comparing, we see that the packages take around 10Mbytes, most of which comes from xCore`:

In[3]:=

Out[3]=

In[4]:=

Out[4]=

Note the structure of the ContextPath. There are several contexts: xAct`xPerm` contains the new reserved words. xAct`xCore` contains my added Mathematica functions. xAct`ExpressionManipulation` is an external package loaded to perform additional expression manipulations.  System` contains Mathematica's reserved words. The current context Global` will contain your definitions (it is now empty).

In[5]:=

Out[5]=

In[6]:=

Out[6]=

In[7]:=

We append the Doc directory of xAct` to the file path to find example files below:

In[8]:=

The Mathematica built-in Timing does not include the time spent in the external executables, though AbsoluteTiming does it. We introduce our own timing function:

In[9]:=

Technical notes:
There are three global variables storing information on the connection to the external executable:

Whether the connection was possible or not is stored in

In[11]:=

Out[11]=

The name of the executable is given by

In[12]:=

Out[12]=

The full description of the link is

In[13]:=

Out[13]=

Created by Mathematica  (May 16, 2008)