This is the keyword "dual" on the OEBP.

Given an example there is some way to "flip sides" by altering it. The left-to-right and right-to-left transformations should be inverses.

It is not required that there only be one such transformation. For example, for many handed Bongard Problem, flipping an example over any axis will reliably switch its sorting.

It is not required that every left example must have its corresponding right example uploaded on the OEBP nor vice versa. See the keyword contributepairs for the BPs the OEBP advises users upload left and right examples for in pairs.

Adjacent-numbered pages:
BP529 BP530 BP531 BP532 BP533  *  BP535 BP536 BP537 BP538 BP539

meta (see left/right), links, keyword, sideless

bp [smaller | same | bigger]

Aaron David Fairbanks

Left examples have the keyword "handed" on the OEBP.

If mirroring any example along the any axis can change its sorting the BP is "handed."

Note that BPs about comparing orientation between multiple things in one example fit on the right side.

See BP871 for the version with pictures of Bongard Problems (miniproblems) instead of links to pages on the OEBP.

The keyword leftright is specifically about flipping over the vertical axis, while the keyword updown is specifically about flipping over the horizontal axis.

Bongard Problems tagged rotate are usually "handed", since any rotation can be created by two reflections. Not necessarily, however, since the reflected step in between might not be sorted on either side by the Bongard Problem.

Adjacent-numbered pages:
BP547 BP548 BP549 BP550 BP551  *  BP553 BP554 BP555 BP556 BP557

meta (see left/right), links, keyword, invariance, wellfounded

visualbp [smaller | same | bigger]
zoom in left (handed_visualbp)

Aaron David Fairbanks

Adjacent-numbered pages:
BP652 BP653 BP654 BP655 BP656  *  BP658 BP659 BP660 BP661 BP662

meta (see left/right), links, metaconcept, primitive

bp [smaller | same | bigger]

Harry E. Foundalis

Adjacent-numbered pages:
BP756 BP757 BP758 BP759 BP760  *  BP762 BP763 BP764 BP765 BP766

meta (see left/right), links, metaconcept

bp [smaller | same | bigger]

Harry E. Foundalis

Adjacent-numbered pages:
BP758 BP759 BP760 BP761 BP762  *  BP764 BP765 BP766 BP767 BP768

meta (see left/right), links, metaconcept, primitive

bp [smaller | same | bigger]

Harry E. Foundalis

Alternatively, BP pages on the OEBP with number less than or equal to 100 vs. other BP pages.

Bongard's original Problems have the keyword "bongard" on the OEBP.

Adjacent-numbered pages:
BP793 BP794 BP795 BP796 BP797  *  BP799 BP800 BP801 BP802 BP803

meta (see left/right), links, keyword

bppage [smaller | same | bigger]

Aaron David Fairbanks

Bongard Problems sorted left obtain the keyword "viceversa" on the OEBP.

Contrast the keyword notso.

"Viceversa" BPs are often dual.

The solution to a less-than/greater-than quantity comparison Bongard Problem (keyword spectrum) where the two sides divide the spectrum in half can be phrased as "closer to left end of spectrum than right end vs. vice versa." Whether this is a natural way to phrase the solution depends on the kind of quantity being compared.

Here are some examples of spectra for which the "vice versa" phrasing tends to seem natural: left vs. right, up vs. down, black vs. white, higher quantity of [thing type 1] vs. higher quantity of [thing type 2].

Adjacent-numbered pages:
BP1157 BP1158 BP1159 BP1160 BP1161  *  BP1163 BP1164 BP1165 BP1166 BP1167

notso, meta (see left/right), links, keyword, right-self

Aaron David Fairbanks

Alternatively, BP pages on the OEBP with number less than or equal to 394 vs. other BP pages.

https://www.foundalis.com/res/bps/bpidx.htm

Adjacent-numbered pages:
BP1189 BP1190 BP1191 BP1192 BP1193  *  BP1195 BP1196 BP1197 BP1198 BP1199

Foundalis's collection includes all Bongard Problems by Bongard.

meta (see left/right), links, right-self, time

Aaron David Fairbanks