File:Quasitransitive 25 percent margin.gif

Page contents not supported in other languages.
This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Original file(1,669 × 1,002 pixels, file size: 44 KB, MIME type: image/gif)

Summary

Description
English: Depicts the relation xRy defined by x5/4y on natural numbers.

R is quasitransitive: Let x5/4y and y5/4z, but y > 5/4x and z > 5/4y. Then x5/4y < z5/4z, but z > 5/4yy > 5/4x.

For this reason, R can be written as the disjoint union of some symmetric relation J and some transitive relation P, and P can be chosen minimal with that property. The minimal P can be obtained by defining xPy by x < 4/5y for natural numbers x, y.

In the picture, xRy holds if the entry in line x, column y is not a red "·". If this entry is a green "P", even xPy holds. If this entry is a blue "I", "T", or "=", even xJy holds.

Given x, the set of numbers "indistinguishable" from x, i.e. { y: xJy }, equals the set of natural numbers in the interval [4/5x...5/4x]; thus it grows arbitrarily large if x is chosen appropriately. In the picture, the blue parts of horizontal slices grow arbitrarily wide.

Nevertheless P is a semiorder: It is asymmetric (semiorder axiom 1), since x < 4/5y < 16/25x is impossible for natural numbers. It satisfies semiorder axiom 2, since w < 4/5x and x4/5y and y4/5x and y < 4/5z implies w < 4/5xy < 4/5z. It satisfies semiorder axiom 3, since for x < 4/5y and y < 4/5z and arbitrary w, we have either w < 4/5z, meaning wPz, or w4/5z, implying x < 4/5y < 16/25z4/5w, that is xPw.

The union of P and all pairs that are incomparable with respect to P yields R again.
Date
Source Own work
Author Jochen Burghardt

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

19 April 2018

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current08:46, 20 April 2018Thumbnail for version as of 08:46, 20 April 20181,669 × 1,002 (44 KB)Jochen Burghardtenhanced color contrast
11:23, 19 April 2018Thumbnail for version as of 11:23, 19 April 20181,669 × 1,002 (44 KB)Jochen BurghardtUser created page with UploadWizard
The following pages on the English Wikipedia use this file (pages on other projects are not listed):

Global file usage

The following other wikis use this file: