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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

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

BP1118 Self-similar only scaled about one point vs. multiple centers of self-similarity.
(edit; present; nest [left/right]; search; history)
COMMENTS

There is only ever one such center of self-similarity or infinitely many.

CROSSREFS

Adjacent-numbered pages:
BP1113 BP1114 BP1115 BP1116 BP1117  *  BP1119 BP1120 BP1121 BP1122 BP1123

KEYWORD

nice, perfect, infinitedetail

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

WORLD

[smaller | same | bigger]

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

BP1115 Fractals tile one another vs. not so (fractals are rather tiled by some combination of one another and themselves).
(edit; present; nest [left/right]; search; history)
COMMENTS

Rotations and reflections avoided in all examples for simplicity.

CROSSREFS

Adjacent-numbered pages:
BP1110 BP1111 BP1112 BP1113 BP1114  *  BP1116 BP1117 BP1118 BP1119 BP1120

KEYWORD

perfect, infinitedetail, unorderedpair

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

AUTHOR

Aaron David Fairbanks

BP1114 Fractals contain one another vs. only one contains the other.
(edit; present; nest [left/right]; search; history)
CROSSREFS

Adjacent-numbered pages:
BP1109 BP1110 BP1111 BP1112 BP1113  *  BP1115 BP1116 BP1117 BP1118 BP1119

KEYWORD

perfect, infinitedetail, unorderedpair

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

AUTHOR

Aaron David Fairbanks

BP1110 The process that turns one object into the other is the same both ways vs. the process changes depending on which object is chosen as the starting point.
?
(edit; present; nest [left/right]; search; history)
REFERENCE

https://en.wikipedia.org/wiki/Duality_(mathematics)

https://en.wikipedia.org/wiki/Involution_(mathematics)

CROSSREFS

This is a special case of BP841 and a generalisation of BP822.

Adjacent-numbered pages:
BP1105 BP1106 BP1107 BP1108 BP1109  *  BP1111 BP1112 BP1113 BP1114 BP1115

KEYWORD

nice, abstract, math, anticomputer, creativeexamples, left-narrow, unorderedpair, rules, miniworlds, dithering

CONCEPT function (info | search)

AUTHOR

Leo Crabbe

BP1109 Considering only the ways they are connected, anything that can be said about a given edge can be said about every other edge vs. not so.
(edit; present; nest [left/right]; search; history)
REFERENCE

https://mathworld.wolfram.com/Edge-TransitiveGraph.html

CROSSREFS

Adjacent-numbered pages:
BP1104 BP1105 BP1106 BP1107 BP1108  *  BP1110 BP1111 BP1112 BP1113 BP1114

KEYWORD

precise, allsorted, notso, math, left-narrow, preciseworld

CONCEPT graph (info | search),
distinguishing_crossing_curves (info | search)

WORLD

graph [smaller | same | bigger]

AUTHOR

Leo Crabbe

BP1108 Solid chunk of black space in neighborhood of any point of the fractal vs. solid chunk of white space in any neighborhood.
?
?
?
(edit; present; nest [left/right]; search; history)
CROSSREFS

Adjacent-numbered pages:
BP1103 BP1104 BP1105 BP1106 BP1107  *  BP1109 BP1110 BP1111 BP1112 BP1113

KEYWORD

right-null, perfect, infinitedetail, assumesfamiliarity, both, neither

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

WORLD

fractal [smaller | same | bigger]

AUTHOR

Aaron David Fairbanks

BP1107 Contains smaller copy of self with black and white inverted vs. not so.
(edit; present; nest [left/right]; search; history)
COMMENTS

There are various problematic cases left out. Are black and white to be inverted within a fractal's convex hull or its outermost outline?

Must this outline be preserved around the smaller inverted version of the fractal, or is it allowed to bleed into other white areas?

No examples have been included in this Bongard Problem whose placement depends on these questions.

CROSSREFS

Adjacent-numbered pages:
BP1102 BP1103 BP1104 BP1105 BP1106  *  BP1108 BP1109 BP1110 BP1111 BP1112

KEYWORD

perfect, infinitedetail

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

WORLD

fractal [smaller | same | bigger]

AUTHOR

Aaron David Fairbanks

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