# Tag Info

Found the solution. The problem was somehow in the variables $\mu[i]$, so instead i used variables automatically generated variables Unique["\[Mu]"] which are unique and are numbered in way $\mu 12, \mu 35, ...$, so there is no problem with brackets. Also it was needed to call evaluate inside Do. PartialDerivative[tensor_] := Module[ {tens = tensor, ...