login
Hints
(Greetings from The On-Line Encyclopedia of Bongard Problems!)
Search: ex:EX9055
Displaying 1-6 of 6 results found.     page 1
     Sort: id      Format: long      Filter: (all | no meta | meta)      Mode: (words | no words)
BP532 Self-tiling fractal using one size of tile vs. does not tile itself with a single size of itself.
(edit; present; nest [left/right]; search; history)
CROSSREFS

This is BP344 ("rep-tiles") but for fractals.

See BP1119 for the version with multiple different sizes of tile allowed.

Adjacent-numbered pages:
BP527 BP528 BP529 BP530 BP531  *  BP533 BP534 BP535 BP536 BP537

KEYWORD

hardsort, proofsrequired, perfect, infinitedetail, contributepairs

CONCEPT fractal (info | search),
recursion (info | search),
self-reference (info | search),
tiling (info | search)

WORLD

[smaller | same | bigger]
zoom in left (fractal_self_tile)

AUTHOR

Aaron David Fairbanks

BP1116 Contains self somewhere within any area around any point within self vs. not so.
(edit; present; nest [left/right]; search; history)
COMMENTS

Very similar to the less clearly-defined solution "tiles itself with infinitely many copies (different sizes allowed) vs. does not".


The left hand side of this is a weaker condition than the left hand side of BP1241.

CROSSREFS

Adjacent-numbered pages:
BP1111 BP1112 BP1113 BP1114 BP1115  *  BP1117 BP1118 BP1119 BP1120 BP1121

KEYWORD

notso, perfect, infinitedetail

CONCEPT topological_density (info | search),
fractal (info | search),
recursion (info | search),
self-reference (info | search)

WORLD

connected_fractal [smaller | same | bigger]

AUTHOR

Aaron David Fairbanks

BP1119 Tiled by finitely many smaller copies of itself (different sizes allowed) vs. not so.
(edit; present; nest [left/right]; search; history)
COMMENTS

These are sometimes called "irreptiles".

CROSSREFS

See BP532 for the version with only one size of tile allowed.

Adjacent-numbered pages:
BP1114 BP1115 BP1116 BP1117 BP1118  *  BP1120 BP1121 BP1122 BP1123 BP1124

KEYWORD

hardsort, proofsrequired, perfect, infinitedetail

CONCEPT fractal (info | search),
recursion (info | search),
self-reference (info | search),
tiling (info | search)

WORLD

[smaller | same | bigger]

AUTHOR

Aaron David Fairbanks

BP1120 No same-sized copies of self overlap vs. distinct same-sized copies overlap.
(edit; present; nest [left/right]; search; history)
COMMENTS

With mathematical jargon:

No distinct same-sized copies of self overlap on a subset with positive measure in the Hausdorff measure using the Hausdorff dimension.


For a covering of a fractal by finitely many scaled down copies of itself, the condition of that no two have an intersection with positive measure is equivalent to the condition that the Hausdorff dimension coincides with the similarity dimension.

(There is another similar condition in this context called the "open set condition" which implies this but is not equivalent. The open set condition is equivalent to the condition that the Hausdorff measure using the similarity dimension is nonzero.)

REFERENCE

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

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

CROSSREFS

Adjacent-numbered pages:
BP1115 BP1116 BP1117 BP1118 BP1119  *  BP1121 BP1122 BP1123 BP1124 BP1125

KEYWORD

challenge, perfect, infinitedetail

CONCEPT fractal (info | search),
recursion (info | search),
self-reference (info | search),
overlap (info | search)

WORLD

[smaller | same | bigger]

AUTHOR

Aaron David Fairbanks

BP1239 Fractal topologically closed (each white point has a neighborhood of pure white surrounding it) vs. not
(edit; present; nest [left/right]; search; history)
COMMENTS

It isn't possible to unambiguously communicate whether or not a few specific points are missing.

CROSSREFS

Adjacent-numbered pages:
BP1234 BP1235 BP1236 BP1237 BP1238  *  BP1240 BP1241 BP1242 BP1243 BP1244

KEYWORD

notso, perfect, infinitedetail

CONCEPT fractal (info | search)

AUTHOR

Aaron David Fairbanks

BP1241 Any point contained in (arbitrarily) smaller version of self vs. not so.
(edit; present; nest [left/right]; search; history)
COMMENTS

Note if any point is contained in some smaller version of the whole, then any point is contained in arbitrarily smaller versions of the whole.


It isn't possible to unambiguously communicate in a picture whether or not a few specific points are included in the fractal. The pictures are interpreted as what is intuitively simplest. To make matters less ambiguous, all the fractals here contain all points arbitrarily close to points in them. (They are topologically closed. See also BP1239.)


The left hand side of this is a stronger condition than the left hand side of BP1116.

CROSSREFS

Adjacent-numbered pages:
BP1236 BP1237 BP1238 BP1239 BP1240  *  BP1242 BP1243 BP1244 BP1245 BP1246

KEYWORD

notso, perfect, infinitedetail

CONCEPT fractal (info | search),
recursion (info | search),
self-reference (info | search)

WORLD

connected_fractal [smaller | same | bigger]

AUTHOR

Aaron David Fairbanks

    page 1

Welcome | Solve | Browse | Lookup | Recent | Links | Register | Contact
Contribute | Keywords | Concepts | Worlds | Ambiguities | Transformations | Invalid Problems | Style Guide | Goals | Glossary