No indication, that I can find, what the diamond characters mean at the end certain sections.

[raymondj-pace]

Describe the mistake There are diamond characters at various points in the book. I do not see any footnotes or anything to indicate their purpose.

Location Please provide the

1. version - Paperback ISBN 978-1-108-45514
2. Chapter 2
3. Page 12
4. 5th text line from the top of page

Proposed solution An indication as to what these diamond symbols indicate.

Additional context Add any other context about the problem here.

[chengsoonong]

The diamond symbols indicate the end of that particular part of text. In the example you pointed out, it "closes" the Remark on geometric systems of linear equations.