This site is published by Eigenia B.V., a private limited company established in Amsterdam, the Netherlands. The registered address and the tax identifier are in section 10.

It is a publication. Eigenia is an applied complexity and mathematical physics research group, and this site carries its corpus: 117 treatises across 10 working groups, together with the standards work, notes and reference material that surround them. Reading it costs nothing, requires no account and creates no relationship between the reader and Eigenia.

A treatise here is research. It is not an engineering instruction for a particular plant, a safety case, an audit finding, a legal opinion, or a substitute for the judgement of a qualified person who is accountable for a real system. Several of the papers concern infrastructure where a mistake has physical consequences, which is exactly why this has to be said plainly rather than buried.

Read the corpus as argument and method. Test anything you intend to rely on against your own system, your own data and your own responsible engineers. Eigenia does not warrant that any of it is free of error, and a reader who finds one is asked to write rather than to quietly work around it.

You are welcome to read the site, link to any page on it, quote it and pass it on. The deep links are stable and are meant to be used, and there is no need to ask first.

You are asked not to interfere with the site or the servers behind it, not to place automated load on it that a reader would not, and not to use the contact forms for bulk or unsolicited mail. The forms are rate limited for that reason, and not because a genuine correspondent has ever been the problem.

The 117 treatises are published under the Creative Commons Attribution 4.0 International licence. That licence, and not these terms, governs what a reader may do with their text, and it permits a great deal, including commercial use. What it allows and the one condition it attaches are set out on the corpus licence page.

The licence on the treatises covers the treatises. It does not cover this site's own source code, its design and interface work, its illustrations, or the name Eigenia. Those are not offered under it, and anyone who wants to use them is welcome to ask.

Where a treatise quotes, cites or reproduces material that Eigenia did not write, that material stays under whatever terms it already carries. The corpus licence cannot extend to it and does not try to. The citations in each paper are there so that a reader can go to the source and check.

The corpus is worked on. A treatise may be revised, corrected or withdrawn, and a page that exists today may not exist in the same form next year. Anyone citing this work is encouraged to record the date they read it, which is why the attribution line on the licence page has a place for one.

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Questions about these terms, and anything else, go to the same address.