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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples considered for sorting. One can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any such formalization. The label "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. Just because one can draw a square badly does not mean "triangle vs. quadrilateral" (BP6) should be called fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. One can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any such formalization. The label "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. Just because one can draw a square badly does not mean "triangle vs. quadrilateral" (BP6) should be called fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. One can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any such formalization. The label "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. Just because one can draw a square badly does not mean "triangle vs. quadrilateral" (BP6) is fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. One can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any such formalization. The label "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. One can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any such formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. One can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) In these cases there is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example. Different ways of formalizing will have slightly different consequences, while Bongard Problems by design communicate ideas without fixing any formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (No unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing a formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case; no unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing a formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case; no unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without any formalization fixed. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case; no unsorted border cases is the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case; the keyword "wholesort" left-BP509 is for no unsorted border cases.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "wholesort" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining the collection of examples that ought to be considered for sorting. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem would sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in drawn images should generally not be considered when deciding whether a BP is exact or fuzzy. The case of a poorly drawn square does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar vagueness arises in all hand-drawn BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy--similar situations arise in practically all BPs. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.)

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules to specify what should count as a relevant example; different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.) The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy.

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules that specify what should count as a relevant example. Different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.) The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy.

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a precise criterion used to verify a sorted example fits where it fits--some kind of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules that specify what should count as a relevant example. Different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.) The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy.

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a clear criterion used to verify a sorted example fits where it fits--some sort of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what is the collection of examples that ought to be sorted. A person can try to come up with increasingly thorough rules that specify what should count as a relevant example. But different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.) The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy.

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a clear criterion used to verify a sorted example fits where it fits--some sort of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what the collection of examples that ought to be sorted is. A person can try to come up with increasingly thorough rules that specify what should count as a relevant example. But different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (This BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.) The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy.

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a clear criterion used to verify a sorted example fits where it fits--some sort of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.

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

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

In an exact BP, any relevant example is either clearly sorted left, clearly sorted right, or clearly not sorted. (Unsorted border cases are allowed in exact BPs, but it must be clear what counts as a border case--contrast the keyword "whole" left-BP509.)

How is it decided whether or not a rule is exact? There would need to be another rule determining what the collection of examples that ought to be sorted is. A person can try to come up with increasingly thorough rules that specify what should count as a relevant example. But different ways of formalizing have slightly different consequences, and Bongard Problems by design communicate ideas without fixing the formalization. The keyword "exact" can only mean a BP's rule seems precise to those who see it. (The BP "exact vs. fuzzy" is fuzzy.)

An exact spectrum-related BP (keyword "spectrum" left-BP507) usually means the sides take either side of an apparent threshold. For example, there is an intuitive threshold between acute and obtuse angles.

Imperfections in images should generally not be considered when deciding whether a BP is exact or fuzzy. (For Bongard Problems in which fine subtleties of drawings, including small imperfections, are meant to be considered, use the keyword "imperfectionsmatter" left-BP913.) The potential for somebody to ask whether a poorly drawn square counts as a quadrilateral does not make "triangle vs. quadrilateral" (BP6) fuzzy.

On the other hand, there are indeed many fuzzy BPs specifically about approximation (e.g. BP10: approximately triangular outline vs. approximately convex quadrilateral outline).

Sometimes the way a Bongard Problem should sort some examples is an unsolved problem in mathematics. (See e.g. BP820.) There is a clear criterion used to verify a sorted example fits where it fits--some sort of mathematical proof. However, it is unclear where some examples fit. Whether or not such a BP should be labelled "exact" might be debated.