26 May
2019
26 May
'19
1:02 p.m.
On Sun, 26 May 2019 10:23:56 +0000, Feng Feng <F.Feng@outlook.com> said:
FF> Thanks very much for your so quick reply. Yes, my mistake, I FF> actually mean A^{abc}_{c} = A^{abcd} * g_{dc} FF> So it goes back to my original post, it seems GiNaC will not FF> produce a 0 result. Raising-lowering indices can break symmetry of tensors, see the second answer here: https://physics.stackexchange.com/questions/315970/is-a-tensor-which-is-symm... -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/