Left examples have the keyword "notso" on the OEBP.
We cannot expect to include all the fitting left examples on the OEBP here.
"Not so" Problems are closely related to "whole" Problems (left-BP509).
blimp
Qat
Bongard Problems with solution most naturally expressed as "___ vs. not so" vs. not so.
Aaron David Fairbanks
Bongard Problems with "world" four dots vs. other Bongard Problems
Dots are as described in BP536.