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• CommentRowNumber1.
• CommentAuthoratmacen
• CommentTimeJan 20th 2019

The example of $Q$ as a Bishop set on the preset $Z \times Z$ is wrong. You need to rule out zero denominators. The definition currently on the page is not a Bishop set at all, because $0/0$ makes the relation intransitive.

I’m not sure how it should be changed to illustrate the point that the same preset can get distinct sets. Maybe a different example entirely?

• CommentRowNumber2.
• CommentAuthoratmacen
• CommentTimeJan 20th 2019

Oh wait. False alarm. That text is using $Z$ for positive integers only.

• CommentRowNumber3.
• CommentAuthorAli Caglayan
• CommentTimeJan 21st 2019

That’s a weird convention, probably best to change it no?

• CommentRowNumber4.
• CommentAuthoratmacen
• CommentTimeJan 21st 2019

Changed the notation in the example that confused me: added “+” superscripts to the (pre)set symbols.

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