Dear Vladimir, On 06/05/2011 06:55 AM, Vladimir V. Kisil wrote:
On Sun, 05 Jun 2011 00:19:51 +0200, "Richard B. Kreckel"<kreckel@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.
Thanks for the concise reminder.
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.
That, as opposed to making the clifford constructor accept both varidx and idx, would require changes to clifford_moebius_map and to the tutorial. Either way, can you recommend a patch? -richy. -- Richard B. Kreckel <http://www.ginac.de/~kreckel/>