DefMetric[-1, gb[-a, -b], CD, SymbolOfCovD -> {"D", "⌡"}]
valueEta = {{-1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}};
AllComponentValues[gb[{a, cartesian}, {b, cartesian}], valueEta];
After all I just simply defined a vector field as
DefTensor[A[μ], M4]
and I tried to make all possible contractions as
epsilongb[μ, ν, α, β] gb[ρ, σ] gb[γ, δ]A[-μ] A[-ν] (CD[-α][A[-β]]) (CD[-ρ][A[-σ]]) (CD[-γ][A[-δ]] //ContractMetric // PutScalar // Simplification // FullSimplify
The "problem" is that I obtained results as
There is any way to"force" xact to have all indices contravariant?. I appreciate your kind support.