Left-sorted Problems have the keyword "left-listable" on the OEBP.

All the possible left examples for the BPs on the left side of this problem could be listed in one infinite sequence. Right examples here are Problems for which no such sequence can exist.

This depends on deciding what images should be considered "the same thing", which is subjective and context-dependent.

All examples in this Bongard Problem have an infinite left side (they do not have the keyword left-finite).

The mathematical term for a set that can be organized into an infinite list is a "countably infinite" set, as opposed to an "uncountably infinite" set.

Another related idea is a "recursively enumerable" a.k.a. "semi-decidable" set, which is a set that a computer program could list the members of.

The keyword "left-listable" is meant to be for the more general idea of a countable set, which does not have to do with computer algorithms.

Note that this is not just BP940 (right-listable) flipped.

It seems in practice, Bongard Problems that are left-listable are usually also right-listable because the whole class of relevant examples is listable. A keyword for just plain "listable" may be more useful. Or instead keywords for left- versus right- semidecidability, in the sense of computing. - Aaron David Fairbanks, Jan 10 2023

https://en.wikipedia.org/wiki/Countable_set

See left-finite, which distinguishes between a finite left side and infinite left side.

"Left-listable" BPs are typically precise.

Adjacent-numbered pages:
BP558 BP559 BP560 BP561 BP562  *  BP564 BP565 BP566 BP567 BP568

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

bp_infinite_left_examples [smaller | same | bigger]
zoom in right (left_uncountable_bp)

Leo Crabbe

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

Although everything is arguably related to math, these BP solutions include content that people don't inherently understand without learning at least some mathematics.

Left examples do not technically have "culturally-dependent" content (keyword culture), but knowledge and previous learning plays a role in how easy they are to solve.

Adjacent-numbered pages:
BP566 BP567 BP568 BP569 BP570  *  BP572 BP573 BP574 BP575 BP576

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

bp [smaller | same | bigger]

Aaron David Fairbanks

Adjacent-numbered pages:
BP619 BP620 BP621 BP622 BP623  *  BP625 BP626 BP627 BP628 BP629

meta (see left/right), links, metaconcept

bp [smaller | same | bigger]

Harry E. Foundalis

"Tiling" is placing shapes next to each other without overlap to fill up space or other shapes.

See BP835 for the version with pictures of Bongard Problems instead of links to pages on the OEBP.

Adjacent-numbered pages:
BP701 BP702 BP703 BP704 BP705  *  BP707 BP708 BP709 BP710 BP711

meta (see left/right), links, metaconcept

bp [smaller | same | bigger]

Harry E. Foundalis

Left-sorted Problems have the keyword "right-listable" on the OEBP.

BPs are sorted based on how BP563 (left-listable) would sort them were they flipped; see that page for a description.

See right-finite, which distinguishes between finite right side and infinite right side.

Adjacent-numbered pages:
BP935 BP936 BP937 BP938 BP939  *  BP941 BP942 BP943 BP944 BP945

meta (see left/right), links, keyword

bp_infinite_right_examples [smaller | same | bigger]
zoom in right (right_uncountable_bp)

Leo Crabbe

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

Right examples have the keyword "fixedgrid" on the OEBP.

See also sequence versus fixedsequence.

Adjacent-numbered pages:
BP1171 BP1172 BP1173 BP1174 BP1175  *  BP1177 BP1178 BP1179 BP1180 BP1181

meta (see left/right), links, keyword

visualbp [smaller | same | bigger]

Leo Crabbe

Adjacent-numbered pages:
BP1172 BP1173 BP1174 BP1175 BP1176  *  BP1178 BP1179 BP1180 BP1181 BP1182

meta (see left/right), links

Leo Crabbe