[GiNaC-devel] indexes of clifford objects

[Vladimir V. Kisil]

		Dear Richard,

>>>>> On Sun, 05 Jun 2011 00:19:51 +0200, "Richard B. Kreckel" <kreckel at ginac.de> said:
    RK> From a physicists point of view, I thought that it doesn't make
    RK> sense to construct a clifford object with an idx instead of a
    RK> varidx.

	There are several mathematical frameworks leading to Clifford
  algebras. Most elementary one is a free algebra with n generators
  factorised by an ideal of the quadratic (anticommuting)
  relations. From that perspective generators of the Clifford algebra
  are not required to be even indexed objects at all. You may call them
  simply a, b, c,... as long as you able to make manipulations like ab=-ba,
  a^2=-1, etc.

    RK> If someone with more insight could shed a light on this I could
    RK> finish my recent quest to make GiNaC pass its test suite even
    RK> when compiled with -DDO_GINAC_ASSERT. That would be great.

	However, I do not see a practical obstacle to change the GiNaC code
  to permit varidx only as indices in the clifford class.

  Best wishes,
  Vladimir
-- 
Vladimir V. Kisil     email: kisilv at maths.leeds.ac.uk
--                      www: http://www.maths.leeds.ac.uk/~kisilv/