M. M. Bongard, Pattern Recognition, Spartan Books, 1970, p. 230.

BP152 is the same solution (with the sides switched), using connected shapes and without black filling.

BP1206 was created to be a slightly different version of this: "vertical axis of symmetry vs. no vertical axis of symmetry." (That less specific solution fits this Bongard Problem as well.)

Adjacent-numbered pages:
BP45 BP46 BP47 BP48 BP49  *  BP51 BP52 BP53 BP54 BP55

nice, stretch, left-narrow, finished, traditional, bongard

curves_and_fill_shapes_separate_drawing [smaller | same | bigger]

Mikhail M. Bongard

This was created to be a slightly different version of BP50, "vertical axis of symmetry vs. no axis of symmetry". The solution for this Bongard Problem is also a (less specific) solution for BP50.

BP1207 is the same solution but using the horizontal axis instead of the vertical axis.

BP1215 is the same solution but with the NW/SE diagonal instead of the vertical axis.

Adjacent-numbered pages:
BP1201 BP1202 BP1203 BP1204 BP1205  *  BP1207 BP1208 BP1209 BP1210 BP1211

stub, notso, stretch, left-narrow, traditional

Aaron David Fairbanks

BP50 is the same solution (with the sides switched), using multiple shapes and with some shapes filled in black.

BP1206 is like BP50 but instead of "no axis of symmetry at all" it uses "no vertical axis of symmetry".

Adjacent-numbered pages:
BP147 BP148 BP149 BP150 BP151  *  BP153 BP154 BP155 BP156 BP157

rotate, stretch, traditional

Douglas R. Hofstadter