TGA[]
can be used as input for in dimensions and is transformed into DiracGamma[ExplicitLorentzIndex[0]]
by FeynCalcInternal
.
Overview, GA, DiracGamma.
[] TGA
[] // FCI // StandardForm
TGA
(*DiracGamma[ExplicitLorentzIndex[0]]*)
[] . TGA[] // DiracSimplify TGA