
The goal of the Atlas of Reductive Lie Groups is to provide access to the
representation theory of real reductive Lie groups. For the moment, these
are defined to be the groups of real points of connected complex reductive
groups defined over the real numbers.

At this point, the classification and structure theory of these groups is
availble, as well as the computation of blocks of (translation families of)
representations, and the computation of Kazhdan-Lusztig polynomials for them.

The program works with a command interface. Input is done through the GNU
readline library, so that the usual facilities of line-editing, arrow-history
and tabbed command completion are available.

Most commands of the program operate in a special "mode" that is apparent from
the prompt that appears. The main function of modes is that they have
associated data that the program remembers. The initial mode "empty" has no
associated data; the subsequent "main" mode records a complex reductive group
and in inner class of real forms; the "real" mode also records a specific real
form in the inner class, and the associated Cartan classes; finally the
"block" mode records in addition a dual real form, so that a unique block of
representations is determined, which block, and when computed the associated
matrix of Kazhdan-Lusztig polynomials, are recorded in this mode. All these
modes make the same set of commands available; when a command for a more
specialized mode is invoked, the program automiatically enters the mode(s)
required for it, asking the user to select the associated data. One other mode
provides a completely different behavior: the in "help" mode, which can be
entered from any other mode by using the command 'help', each command name
just prints a description of what the command does. The general method to exit
a mode is by using the command 'q'; this returns to the next less specialized
mode (forgetting the data associated to the current mode), or in case of the
help mode to the mode from which 'help' was invoked. The command 'qq' provides
a way to exit the program completely, from any mode except the help mode.
