> g:=evalDG(Theta1 &t Theta1 + Theta2 &t Theta2 + Theta3 &t Theta3);
#covariant metric in the orthonormal basis

> g_cv:=evalDG(E1 &t E1 + E2 &t E2 + E3 &t E3); #contravariant metric in the orthonormal basis

> C := Christoffel(g); #Connection

> A:=evalDG(B[1]*E1+B[2]*E2+B[3]*E3); #contravariant vector

> DA:=CovariantDerivative(A,C): #covariant derivative of the above vector with the chosen basis
> divA:=expand(ContractIndices(DA,[[1,2]]));

> A:=evalDG(B[1]*Theta1+B[2]*Theta2+B[3]*Theta3);#covariant vector

> DA:=CovariantDerivative(A,C):#covariant derivative of the above covariant vector with the chosen connection
> epsilon:=PermutationSymbol("con_bas");#skew symmetric tensor