• Original written for this handbook, with no specific source.
• Adapted rewritten in our own words; the block names the work and pages it follows.
• Quoted a short verbatim excerpt, cited to the page.

Provenance and copyright

This handbook is written from a library of published textbooks. Those books are copyrighted, and we do not reproduce them. Everything here is either written for the handbook or rewritten in our own words, and every passage says which of those it is.

How each block is labelled

Every block of every unit (each definition, statement, proof, example and so on) carries one of three labels:

• Original: written for this handbook with no specific source. Our own worked examples, exercises, applications and remarks are original.
• Adapted: written in our own words, but the content (a theorem, the route of a proof, a method) follows a particular book. The block names the book and the pages it follows.
• Quoted: a short verbatim excerpt (at most two sentences, at most 60 words), in quotation styling, cited to the page. Used only when the exact wording matters, for example a definition whose phrasing has become standard.

Each unit also ends with its full list of sources, and every book cited anywhere is listed under Sources with the exact edition used.

What we do not copy

• Prose. We do not copy sentences. Where an author's own phrasing is itself the point — a term whose wording has become standard, or a hedge we want to report exactly — a short phrase appears in quotation marks and cited to the page, inside the block that discusses it; anything longer belongs in a Quoted block. Everything else is our own wording. No passage of ours, quoted phrases aside, shares twelve consecutive words with any book in the library, and this is checked rather than assumed.
• Proofs and derivations. Mathematical facts are not anyone's property, but the way a book presents them is. Adapted proofs are re-structured and re-worded: we state the idea first, then give the steps in our own order and notation. The book whose approach we follow is cited.
• Worked examples and exercises. We write new ones, with different set-ups and numbers. If one is modelled on a book's example, it is labelled Adapted and cited.
• Figures. Never copied. Ours are drawn from scratch; if a figure is modelled on a book's figure, it says so.
• Structure. The handbook's organisation into parts, chapters, sections and units is our own and does not follow any one book's table of contents.

How this is enforced

Citing a source does not by itself make copying acceptable, so the rules above are checked by software before anything is published:

1. Labels are mandatory. A unit with any block lacking a label, an Adapted block without a source, or a source that is not in the bibliography does not build.
2. Verbatim check. The prose of every unit (with mathematical formulas removed) is compared against the full text of every book in the library, not just the books it cites. A run of twelve or more consecutive words that also appears in a book fails the unit, and so do twenty or more shared words in one block. Shorter shared runs of eight words or more are flagged for a reviewer, because the standard wording of a definition or theorem ("with equality if and only if f and g are linearly dependent") is often that long. Phrases found in three or more different books are treated as stock phrases.
3. Close-paraphrase check. Every block is aligned word by word against the pages it cites and against the pages most similar to it. A block that follows a book passage closely in order, even with many words changed, fails. A block that is merely similar is flagged and must be compared with that passage by a reviewer.
4. Independent review. Before a unit is published, two independent reviewers check its mathematics and its citations, and confirm that adapted blocks are genuinely rewritten. Any later edit sends the unit back through all of these checks.

These checks reduce the risk of accidental copying; they do not replace judgement, and this page is not legal advice.

The source books themselves

The books are used only as reference material by the authors of this handbook. They are not distributed with it, and no text extracted from them is published.

If you hold rights in a cited work

If you are an author or publisher of a work cited here and you believe a passage reproduces your material rather than reporting it, please tell us and we will act on it quickly.

• Contact: sumangalamavtarsharma@gmail.com
• Please name the unit (its URL or id) and the block, and the passage and page in your work.
• We will re-review the block against your work, and where the complaint is sound we will rewrite or remove it. A removed or rewritten unit is sent back through the full set of checks and both reviewers before it is published again.

We would rather hear from you than not. The checks described above reduce the risk of accidental copying; they do not eliminate it, and a rightsholder is better placed than any of our tools to recognise their own material.

Licence of our own text

The handbook's own text (every Original and Adapted block, and the organisation of the handbook) is licensed under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). You may share and adapt it, with credit and under the same licence.

Quoted blocks are not covered: they remain under their original copyright. The licence also grants no rights in the cited books; it covers only our wording.

What this build contains

Counted from the 360 published unit(s) of this build, not asserted:

Figures: 0.

No block in this build is labelled Quoted. Short quotations from a cited work do appear inline inside Adapted blocks, always in quotation marks and cited to the page, where an author's own phrasing is the point. They are the exception, not the method.

What the publication gate guarantees about this build, by construction rather than by assertion: every unit here was compared against the full text of all cited works, and none contains a run of twelve or more consecutive words shared with any of them, nor a block that tracks a source passage closely in order. A unit failing either check cannot reach this page.

It contains no figures.