How to gnerate an error if a layer does not exist in the layout

Version 1

    Two options:
    ===========
    1) full_chip = EXTENT DRAWN ORIGINAL
        Oxide_empty {  @Oxide must exist in layout
            full_chip NOT INTERACT oxide
        }

     

    OR:

     

    2) full_chip = EXTENT DRAWN ORIGINAL
        Oxide_empty {   @Oxide must exist in layout
            DFM PROPERTY full_chip oxide [ x = COUNT (oxide)] == 0
        }