Note that most traditional Bongard Problems don't sort an all black-panel at all.
See BP567 (left-null versus right-null) for the version about all-white panels, which is more often applicable.
Adjacent-numbered pages: BP1155 BP1156 BP1157 BP1158 BP1159  *  BP1161 BP1162 BP1163 BP1164 BP1165
meta (see left/right), links, side, testexample
Leo Crabbe