Bongard Problems with "world" one simple closed 2D shape outline vs. other Bongard Problems.
"Simple" means the same as in BP528, but here holes in the shape are not allowed.
Bongard Problems with "world" one simple closed 2D shape outline.
Bongard Problems with "world" one simple 2D shape outline.
Bongard Problems with "world" single simple 2D shape outline.
Bongard Problem with "world" single simple 2D shape outline.