# Functional dependence

Hi friends,

I would like to know if is there any possibility of defining a functional dependence for an object. For example, in the below code the Cadabra throws an error

x::Coordinate;
\partial{#}::PartialDerivative;
\bar{#}::DiracBar;
{\phi,J, j, \eta}::Depends(x, \partial{#});
S::Depends(\phi,\bar{\eta},\eta);


Regards

If you want to know whether there is anything that can help you to do vary combined with automatic integration by parts to isolate the variational derivative, then the answer currently is 'no'. There will be something soon, as this is obviously something people expect, but we haven't settled yet on the details of the solution.