The On-Line Encyclopedia of Bongard Problems

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Tessellates the plane vs. does not tessellate the plane.

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	COMMENTS	`EX7152 is an example of a shape than can be stretched in such a way that it no longer tessellates the plane. This is a property that is only exhibited by shapes that tessellate with rotated copies of themselves. - Leo Crabbe, Mar 05 2021`
	CROSSREFS	`Adjacent-numbered pages: BP330 BP331 BP332 BP333 BP334 * BP336 BP337 BP338 BP339 BP340`
	KEYWORD	`nice, stretch, unstable, math, hardsort, creativeexamples, proofsrequired, perfect, pixelperfect, traditional`
	CONCEPT	`infinite_plane (info \| search),` `tessellation (info \| search),` `tiling (info \| search)`
	WORLD	`shape [smaller \| same \| bigger] zoom in left (fill_shape)`
	AUTHOR	`Aaron David Fairbanks`

BP368

There is a point that can see (in straight lines) all points vs. there is no point that can see (in straight lines) all points.

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	COMMENTS	`Left examples are called "star domains."`
	CROSSREFS	`See BP388 for whether a distinguished point can see all points.` `Adjacent-numbered pages: BP363 BP364 BP365 BP366 BP367 * BP369 BP370 BP371 BP372 BP373`
	KEYWORD	`nice, precise, unstable, perfect, traditional`
	CONCEPT	`all (info \| search),` `existence (info \| search),` `imagined_point (info \| search),` `imagined_line_or_curve (info \| search),` `imagined_entity (info \| search)`
	WORLD	`shape [smaller \| same \| bigger] zoom in left (fill_shape_with_seeing_point)`
	AUTHOR	`Aaron David Fairbanks`

BP990

The center of mass can "see" (in straight lines) all points within the shape vs. the center of mass is not located in a region where it can see (in straight lines) all points.

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	COMMENTS	`Another way of thinking about the solution is considering whether a light source placed at the center of mass of a given example would illuminate the whole shape.`
	CROSSREFS	`Every left for this Problem would be will be a left example for both BP367 and BP368.` `Adjacent-numbered pages: BP985 BP986 BP987 BP988 BP989 * BP991 BP992 BP993 BP994 BP995`
	KEYWORD	`convoluted, perfect`
	CONCEPT	`inside (info \| search),` `center_of_mass (info \| search),` `imagined_point (info \| search),` `imagined_line_or_curve (info \| search),` `imagined_entity (info \| search)`
	WORLD	`fill_shape_seeing_point_center_of_mass_inside [smaller \| same \| bigger]`
	AUTHOR	`Leo Crabbe`

BP1212

Shape tiles a square vs. not

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	CROSSREFS	`Adjacent-numbered pages: BP1207 BP1208 BP1209 BP1210 BP1211 * BP1213 BP1214 BP1215 BP1216 BP1217`
	KEYWORD	`precise`
	WORLD	`fill_shape [smaller \| same \| bigger]`
	AUTHOR	`Jago Collins`

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