CAS is an easy to use, general purpose Computer Algebra System, a
program for symbolic manipulation of mathematical expressions. It uses
its own programming language designed for symbolic as well as
arbitrary-precision numerical computations. The system has a library of
scripts that implement many of the symbolic algebra operations; new
algorithms can be easily added to the library. YACAS comes with
extensive documentation (320+ pages) covering the scripting language,
the functionality that is already implemented in the system, and the
algorithms we used.