[GiNaC-devel] clifford patch

[Jens Vollinga]

Hi Vladimir,

I applied your and C.Dams' patch now. But I also applied a forgotten
patch from you from December that changes

ex clifford::get_metric(const ex & i, const ex & j) const

from

return indexed(metric, symmetric2(), i, j);

to

return indexed(metric, i, j);

With this December patch the exams for clifford fail with

----------clifford objects:
2*ONE*[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~nu~mu-2*[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~mu~nu*ONE
erroneously return ed
2*ONE*[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~nu~mu-2*[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~mu~nu*ONE
instead of 0
[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~mu~nu*e~lambda-[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~nu~mu*e~lambda-0
erroneousl y returned
[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~mu~nu*e~lambda-[[-1,0,0,0],[0,0,0,0],[0,0,1,0],[0,0,0,-1]]~nu~mu*e~lambda
i nstead of 0

Without it, it produces no error.

The December patch makes sense to me, because the tutorial promises that
one can use non-symmetric metrics. Am I wrong here? So, what should I do
about it?

Regards,
Jens