{x,y,z}::Coordinate; {i,j,k}::Indices(values={x,y,z}); \partial{#}::PartialDerivative; F_{i j}::Depends(x,y,z); ex:=\partial_{i}{F_{i k}} + m**2 A_{k}; evaluate(ex); produces an output which contains chain rule expression of the type `Derivative(DN(x), x)` because the indices get passed along as arguments.