[Axiom-developer] Re: Commutative symbols

[Ondrej Certik]

> But matrices are different kind of objects. I was talking about just
> noncommutative symbols, for example the  Pauli algebra:
>
> http://en.wikipedia.org/wiki/Pauli_matrices

If you want to look at the actual implementation:

http://sympy.googlecode.com/svn/trunk/sympy/modules/paulialgebra.py

the relevant code (if we won't count comments and helper functions
like delta and epsilon) is below 20 lines. That's what I mean when I
want to have a CAS, that is easily extensible.

Ondrej