DNG Set permission back to 'inherit from parent scope'

I am playing with setting artifact permissions.

I set the view to 'show by operation'

I expand the tree to look at various actions.

For the action selected the list of roles is shown along with each role's permission.

In a new project the permissions for individual roles for any action are initially set to 'inherit from parent scope'.

I can modify this to 'permitted' or 'not permitted'

After I make this modification is it possible to set the permission back to 'inherit from parent scope' ?

If so how can I do this as I cannot see an option other than 'permitted' or 'not permitted'