All examples in this Bongard Problem are outlines of shapes.
M. M. Bongard, Pattern Recognition, Spartan Books, 1970, p. 215.
Adjacent-numbered pages: BP1 BP2 BP3 BP4  *  BP6 BP7 BP8 BP9 BP10
easy, nice, ignoreimperfections, finished, traditional, bongard
shape_outline [smaller | same | bigger]zoom in left (polygon_outline)
Mikhail M. Bongard