 near-depth end gap horizontal boundaries in response to the image in **Figure [00A](#F00){ref-type="fig"}**, it cannot do so in response to the image in **Figure [00B](#F00){ref-type="fig"}** because the D0 far-depth boundary is not closed in this case after surface contour signals act from the D0 vertical rectangular boundary, and thus is not strengthened by its own surface contour feedback signals. The same kind of situation occurs in response to the fragmented inducers in **Figure [0](#F0){ref-type="fig"}**. 