Search: keyword:precise
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BP344 |
| Shape can tile itself vs. shape cannot tile itself. |
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COMMENTS
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Left examples are sometimes called "rep-tiles."
The tiles all must be the same size. More specifically, all left examples can tile themselves only using scaled down and rotated versions of themselves with all tiles the same size. Right examples cannot tile themselves using scaled down rotated versions of themselves or even reflected versions of themselves with all tiles the same size.
Without the puzzle piece-like shape EX4120 on the right side the current examples also allow the solution "shape can tile with itself so as to create a parallelogram vs. shape cannot tile with itself so as to create a parallelogram." |
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CROSSREFS
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See BP532 for a version with fractals.
Adjacent-numbered pages:
BP339 BP340 BP341 BP342 BP343  *  BP345 BP346 BP347 BP348 BP349
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EXAMPLE
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Go to https://oebp.org/files/yet.png for an illustration of how some left-sorted shapes tile themselves. |
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KEYWORD
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hard, precise, notso, unstable, math, hardsort, creativeexamples, proofsrequired, perfect, traditional
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CONCEPT
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recursion (info | search), self-reference (info | search), tiling (info | search), imagined_shape (info | search), imagined_entity (info | search)
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WORLD
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shape [smaller | same | bigger]
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AUTHOR
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Aaron David Fairbanks
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BP348 |
| Shape on the right is the convex hull of shape on the left vs. not so. |
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BP367 |
| Center of mass within the black area of the shape vs. center of mass out of the black area of the shape. |
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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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BP376 |
| A "chess piece" that moves as shown may reach every square vs. not so. |
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CROSSREFS
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Adjacent-numbered pages:
BP371 BP372 BP373 BP374 BP375  *  BP377 BP378 BP379 BP380 BP381
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KEYWORD
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precise, allsorted, notso, left-finite, right-finite, traditional, fixedgrid, preciseworld
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CONCEPT
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all (info | search), chess-like (info | search), imagined_motion (info | search), motion (info | search)
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AUTHOR
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Aaron David Fairbanks
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BP384 |
| Square number of dots vs. non-square number of dots. |
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COMMENTS
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All examples in this Problem are a collection of dots.
An equivalent solution is "Dots can be arranged into a square lattice whose convex hull is a square vs. not so". - Leo Crabbe, Aug 01 2020 |
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CROSSREFS
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Adjacent-numbered pages:
BP379 BP380 BP381 BP382 BP383  *  BP385 BP386 BP387 BP388 BP389
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EXAMPLE
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A single dot fits because 1 = 1*1.
A pair of dots does not fit because there is no integer x such that 2 = x*x. |
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KEYWORD
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nice, precise, allsorted, number, math, left-narrow, left-null, help, traditional, preciseworld, collection
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CONCEPT
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square_number (info | search)
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WORLD
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dots [smaller | same | bigger]
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AUTHOR
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Jago Collins
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BP386 |
| Lower shape can be used as a tile to build the upper one vs. not so. |
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CROSSREFS
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Adjacent-numbered pages:
BP381 BP382 BP383 BP384 BP385  *  BP387 BP388 BP389 BP390 BP391
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KEYWORD
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nice, precise, allsorted, left-narrow, perfect, pixelperfect, orderedpair, traditional, preciseworld, left-listable, right-listable
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CONCEPT
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tiling (info | search)
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AUTHOR
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Jago Collins
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BP389 |
| Loops are entangled (in 3-D) vs. loops can be separated (in 3-D). |
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