Math 2.0

K01, part B. Literature indexes, open textbooks and syllabi: sizes, licences, channels (research for math2)

Status: research note for spec 01 §1.7, spec 09 (all, especially the 9.3 licence gate) and spec 16 §16.6. Read date: every fact below was read on 2026-10-26 unless another date is given. Each fact has a URL next to it. UNVERIFIED means I could not confirm the fact at a primary source. The reason is given each time. Method: WebSearch, WebFetch and a few single curl requests with User-Agent m2/research (+https://github.com/tamnd/math2-agent). There was no crawling and no bulk download. The largest samples were three days of arXiv OAI-PMH set=math (1,421 records), the Open Textbook Library mathematics JSON (22 pages), four Mathlib YAML files, two syllabus PDFs and one zbMATH API query.

This note does not repeat what the spec already says. The spec already has: arXiv about 15% open, s3://arxiv requester-pays and Kaggle CC0; zbMATH 168M triples; Stacks GFDL 1.2 with 21,446 tags; TheoremSearch 9.2M / 690k / 1.34M; TheoremGraph 11.7M / 18.3M / 48k; Matlas 8M / 435k / 1.9k; MSC2020 CC BY-NC-SA; the Stack Exchange no-LLM clause. Where my findings correct or refine those figures, I say so.

The access classes used in the "math2 can take" column are those of spec 9.3: open, share-alike-nc, verbatim, gfdl, record. Node prose is CC BY-SA 4.0, code is Apache-2.0 and metadata is CC0 (16.6).

Part 1. Literature indexes and full text

1.1 arXiv

Bulk and API terms

  • S3 bulk: the bucket arxiv (prefixes pdf/, src/) is requester-pays in us-east-1. Files come as tars of about 500 MB with manifests and are updated about monthly. The total is "about 9.2 TB" as of April 2025, growing by about 100 GB a month. Users "must link back to arXiv for downloads". (https://info.arxiv.org/help/bulk_data_s3.html, https://info.arxiv.org/help/bulk_data.html)
  • API Terms of Use (https://info.arxiv.org/help/api/tou.html; the page carries no date):
    • Metadata is CC0.
    • "The redistribution of e-prints requires permission from the copyright holder." Storing and serving e-prints needs permission or a licence; personal and research use is allowed.
    • The rate limit is one request every 3 seconds on a single connection, counted across all of a user's machines.
    • Users may not claim arXiv endorsement.
  • AI and TDM terms: none of the four arXiv help pages above says anything about AI, LLMs, TDM or training. So for arXiv the per-paper licence is the only AI-relevant term. (A missing clause is not the same as permission. See open doubt D3.)
  • Licence options for authors (https://info.arxiv.org/help/license/index.html):
Licence 9.3 class
CC BY 4.0 open
CC BY-SA 4.0 open
CC0 open
CC BY-NC-SA 4.0 share-alike-nc
CC BY-NC-ND 4.0 verbatim
arXiv non-exclusive distribution licence 1.0 (http://arxiv.org/licenses/nonexclusive-distrib/1.0/) record

New measurement: the 2026 licence mix in math. I harvested three single days from oaipmh.arxiv.org/oai, with verb=ListRecords&metadataPrefix=arXiv&set=math: from=until=2026-10-01, 2026-04-15 and 2026-07-08. That gave 1,421 records. The 1,026 records with 26xx identifiers (papers first submitted in 2026) break down as follows:

Licence Share
non-exclusive (record) 55.3%
CC BY 4.0 34.0%
CC BY-NC-ND 5.9%
CC BY-NC-SA 1.9%
CC0 1.9%
CC BY-SA 1.0%
  • open share for node prose (BY + BY-SA + CC0): 36.9%. By day it was 35.3%, 38.3% and 38.8%. Records with older identifiers that were re-versioned on those days (395 of them) were about 39.2% open.
  • Consequence: the spec's "about 15% of arXiv is open" is the all-time stock. The 2026 flow in math looks more than twice as open. This is a small sample and needs confirmation (D2).
  • Caveats:
    • The OAI datestamp also counts metadata updates, not just new submissions.
    • I did not establish whether set=math includes cross-lists.

1.2 zbMATH Open

  • OAI-PMH: Identify at https://oai.zbmath.org/v1/?verb=Identify works. It reports earliestDatestamp 1755.
  • REST API (https://api.zbmath.org/v1/document/_search):
    • It returns full review text (editorial_contributions) and a per-document license field. That field was empty in my sample.
    • The query py:2025 returns nr_total_results 133,093. That is a reasonable yearly-volume figure for 2025.
  • API terms: https://static.zbmath.org/legal/api-terms-and-conditions.html was blocked by a Cloudflare challenge, and so was https://zbmath.org/about/. The API terms, and any AI clause in them, are UNVERIFIED.
  • Knowledge graph dump (Zenodo record 21497976, concept DOI 10.5281/zenodo.21497975; https://zenodo.org/records/21497976):
    • Published 2026-09-01 and modified 2026-10-24. File zbmath-kg-ttl-2026.tar.gz, 1.6 GB.
    • Built from the January 2026 API dump. It is updated about twice a year, not monthly as spec 9.2 says.
    • A temporary SPARQL endpoint is at http://212.227.170.235:8890/sparql.
    • Repository: https://github.com/zbMATHOpen/zbmath-open-kg. Paper: https://arxiv.org/abs/2609.00969.
    • Stats: 168M+ triples, 34M+ entities, 4M+ publications, 1M+ persons, 3M+ reviews.
    • Restricted abstracts appear as the literal placeholder "zbMATH Open Web Interface contents unavailable due to conflicting licenses".
  • The licence conflict: the Zenodo metadata field says CC BY 4.0, but the record's description says CC BY-SA 4.0 for the dataset, with the I4OC references CC0. The spec says "CC BY-SA 4.0". For math2 both are open. They do differ on whether derived exports must be BY-SA (D1).
  • What math2 can take:
    • Records, MSC codes and links as metadata.
    • Review text is open under either reading. In practice it should be used as evidence and for locators, not pasted into prose. Reviews are third-party texts, and their per-item rights in the API license field are empty or unclear.

1.3 OpenAlex and Unpaywall

  • Snapshot (https://help.openalex.org/download-all-data/openalex-snapshot, page updated 2026-09-24):
    • The bucket s3://openalex is free and anonymous (--no-sign-request). LICENSE.txt in the bucket is CC0 1.0, which I checked.
    • The September 2026 release is about 745 GB of compressed JSONL (works about 615 GB), or about 770 GB in Parquet.
    • The free snapshot is quarterly, on the second Wednesday of January, April, July and October. Daily snapshots are paid.
  • API key and pricing: an API key has been required since 2026-02-13, with usage-based pricing. Partly UNVERIFIED: I found this only in secondary sources (https://casrai.org/news/openalex-api-keys-mandatory-usage-based-pricing-2026). https://help.openalex.org/api/ did not render the details for me.
  • Unpaywall:
    • Unpaywall now runs inside OpenAlex (the "Walden" rewrite), and its data feed is a paid product.
    • The last free standalone Unpaywall snapshot I found is dated 2024-11-27, according to a SUB Göttingen note.
    • https://unpaywall.org/products/snapshot returned an empty page. The current Unpaywall terms are UNVERIFIED.
  • What math2 can take: all of it, as CC0 metadata (works, authors, venues, concepts, OA locations). OpenAlex has no full text.

1.4 Crossref

  • REST API (https://www.crossref.org/documentation/retrieve-metadata/rest-api/): no sign-up is needed. Crossref says "almost none of the metadata is subject to copyright", but "some abstracts ... may be subject to copyright".
  • 2026 public data file (https://www.crossref.org/blog/2026-public-data-file-now-available/, posted 2026-03-17): 180,034,490 records as of 2026-03-14, 208 GB of JSONL. It is distributed via Academic Torrents (doi 10.13003/nggf-vt1j) or AWS.
  • What math2 can take: DOI metadata and reference lists as facts. Abstracts are record unless the item's own licence says otherwise.

1.5 DataCite

  • Public data file: annual and CC0. The use policy asks for credit.
    • The 2025 file was generated on 2026-01-06 and announced on 2026-01-22. It has 108M findable DOIs and is at https://datafiles.datacite.org/.
    • The monthly file is for members only. The file is also on Dimensions' BigQuery.
    • Sources: https://support.datacite.org/docs/datacite-public-data-file, https://support.datacite.org/docs/datacite-data-file-use-policy, and the DataCite blog.
  • What math2 can take: all of it, as metadata. Its use for math2 is datasets and software DOIs (Zenodo and others).

1.6 Semantic Scholar and S2ORC

  • API licence (https://www.semanticscholar.org/product/api/license, "last updated" 2023-05-17):
    • The licence is non-transferable. You may not redistribute or sublicense the API.
    • S2 data is under its own licences, "such as CC BY-NC or ODC-BY". Attribution is required.
    • It has no AI-training clause.
  • S2ORC:
    • https://github.com/allenai/s2orc says ODC-By 1.0 (earlier releases were NC). The Hugging Face card at https://huggingface.co/datasets/allenai/s2orc is tagged cc-by-2.0, which is an inconsistency.
    • Size: a 2026 arXiv paper reports the 2026-05-26 release as having 15,679,781 S2ORC full-text papers.
  • UNVERIFIED:
    • The licence of the separate abstracts dataset (the datasets API docs returned HTTP 429).
    • The current total of papers. A third-party figure for 2025-09 says 200M+ papers and 100M+ abstracts.
  • What math2 can take:
    • Paper ids as crosswalk targets.
    • S2ORC full text is ODC-By as a database, but each paper's text keeps the paper's own copyright. Treat it per paper, by its arXiv or publisher licence. It is never open just because it sits in S2ORC.

1.7 CORE

  • Terms (https://core.ac.uk/terms; I read this via a search snippet because the page returned 403 to curl):
    • Dumps are ODC-By, covering CORE's own database rights only.
    • API access needs a licence; it is free for individuals and for public research.
    • A licensing-framework review proposes CC0/ODC-0 for metadata and "conditional access for lawful TDM" for full texts.
  • Size: 291M metadata records and 32.8M full texts (February 2023, the CORE paper in Scientific Data). The current size and the current dump terms are UNVERIFIED (core.ac.uk/documentation returned 403).
  • What math2 can take: records. Full texts follow each paper's licence, as for S2ORC.

1.8 HAL (France)

  • OAI-PMH (https://api.archives-ouvertes.fr/oai/hal/?verb=Identify): "Metadata is licensed under CC0".
  • Math share, measured by API: a query on level0_domain_s:math returned 170,406 records, 105,413 of them with a file. (The query domain_s:math* returns 0.) The licence facet over the records with a file:
Licence Records 9.3 class
hal-authorisation-v1 (https://about.hal.science/hal-authorisation-v1/) 84,016 record
CC BY 4.0 9,239 open
hal copyright (https://hal.science/licences/copyright/) 4,272 record
CC BY-NC-ND 3,861 verbatim
CC BY-NC 1,796 share-alike-nc
CC BY-NC-SA 731 share-alike-nc
CC0 492 open
CC BY-SA 449 open
CC BY-ND 254 verbatim
Etalab 2.0 163 open (attribution licence, compatible with CC BY)
PDM 6 open
none / empty 113 + 21 record
  • open share: 10,349 / 105,413 = about 9.8%.
  • Channels: REST at api.archives-ouvertes.fr/search, SPARQL at https://data.hal.science/doc/sparql, and OAI-PMH.
  • I found no AI clause.

1.9 Numdam (Mathdoc)

  • Size (https://www.numdam.org/en/): 75,599 articles in 120 periodicals, 706 books in 8 collections, 416 theses, 1,428,508 pages.
  • Moving wall: 2 to 10 years. Mersenne journals arrive after 1 year.
  • Conditions (https://www.numdam.org/conditions/):
    • Metadata is CC0 and can be harvested by OAI-PMH.
    • Full texts are for individual download for research, study or training.
    • Downloading "un volume substantiel" without explicit permission is forbidden, and so is modifying the files.
    • Republishing is allowed only for public-domain items (described as "très rares sur Numdam") and for CC-licensed articles.
  • What math2 can take: records (CC0). Text is record by default, or the per-article CC licence where one is given. Bulk full text is not allowed without permission.

1.10 EuDML

  • UNVERIFIED for current figures. eudml.org, including its OAI endpoint, returned 403 or a Cloudflare challenge.
  • What I could find:
    • Mathdoc's page (https://www.mathdoc.fr/en/realisations/eudml/, undated) says "over 270,000 documents".
    • A 2016 report says 257k items, 252,111 articles and 323 journals.
    • https://eudml.org/journals listed 339 journals in a search snippet.
    • EuDML's policy is to hold only content past its moving wall, with JATS-flavoured OAI. Its metadata licence is UNVERIFIED.
  • What math2 can take: records via the partner sources (Numdam, GDZ, CEDRAM and others) rather than EuDML itself.

1.11 Project Euclid

  • https://projecteuclid.org/about says "over 80% of the journal articles hosted ... are openly available". It is run by Duke University Press.
  • "Openly available" means free to read, not openly licensed. Per-journal licences are UNVERIFIED. Default to record, and use the per-article licence where it is shown (for example, some IMS/Bernoulli journals).

1.12 GDZ (Göttinger Digitalisierungszentrum)

  • Size: over 15M pages, with collections for Mathematica and FID Mathematik (https://gdz.sub.uni-goettingen.de/).
  • IIIF: the manifest for Mathematische Annalen vol. 1 (1869) at https://manifests.sub.uni-goettingen.de/iiif/presentation/PPN235181684_0001/manifest has an attribution but no license field.
  • PDF terms: a generated PDF (https://gdz.sub.uni-goettingen.de/download/pdf/PPN71557308X/LOG_0040.pdf) has a cover page saying reproductions may not be made for other repositories without written permission.
  • The licence of the scans is UNVERIFIED. The underlying 19th-century texts are public domain.
  • What math2 can take: records and locators. Statements from public-domain works, which math2 rewrites anyway. Not the scans.

1.13 The US public-domain line, HathiTrust, Internet Archive, Project Gutenberg

The US public-domain line. Works published in 1930 entered the US public domain on 2026-01-01 (https://web.law.duke.edu/cspd/publicdomainday/2026/). So in 2026, works published in the US before 1931 are public domain in the US. Public domain is open for prose: no attribution is needed, but math2 should give it anyway.

HathiTrust

  • hathitrust.org (terms and acceptable-use pages) is behind Cloudflare. The terms and any AI policy are UNVERIFIED.
  • https://github.com/hathitrust/datasets lists the public-domain text subsets ht_text_pd, ht_text_pd_open_access, ht_text_pd_world and ht_text_pd_world_open_access. The full ht_text is used only by HTRC for non-consumptive research.
  • A related public-domain corpus: Harvard Institutional Books 1.0 has 983,004 public-domain volumes.

Internet Archive

  • Counts from advancedsearch (https://archive.org/advancedsearch.php?q=subject%3Amathematics+AND+mediatype%3Atexts&rows=0&output=json):
    • subject:mathematics AND mediatype:texts gives 206,597 items.
    • Restricting to year:[1500 TO 1930] gives 8,076.
  • https://archive.org/about/terms returned an empty page. The IA terms are UNVERIFIED. Uploads on IA include many in-copyright books. For example, Hatcher's Algebraic Topology is there, though its licence is noncommercial copying only (§2.4). IA hosting therefore says nothing about licence.

Project Gutenberg

  • Robot policy (https://www.gutenberg.org/policy/robot_access.html): the site is "intended for human users only". Bulk users should use a mirror, or wget with -w 2 through /robot/harvest. Catalogue data is public domain.
  • Licence (https://www.gutenberg.org/policy/license.html): "Nearly all the individual works ... public domain in the United States". The trademark licence no longer applies once "all references to Project Gutenberg are removed".
  • Size: about 78,000 items (a 2026-03-22 figure).
  • Mathematics bookshelf 102 (https://www.gutenberg.org/ebooks/bookshelf/102) includes:
    • Hardy, A Course of Pure Mathematics (#38769, with LaTeX source)
    • Dedekind (#21016)
    • Casey's Euclid (#21076)
    • Thompson, Calculus Made Easy
  • What math2 can take: open (public domain in the US) with the Project Gutenberg header removed. The non-US public-domain status of each work is a separate check (D10).

1.14 Extraction projects (TheoremSearch, TheoremGraph and LeanGraph, Matlas, and new ones)

TheoremSearch (https://arxiv.org/abs/2602.05216, v2 dated 2026-03-07)

  • Size: https://theoremsearch.com shows "8.4M" indexed. By source:
Source Statements
arXiv 8,104,539
Lean 285,213
ProofWiki 23,284
Stacks 10,645
Lean Community 1,888
Open Logic 588
CRing 498
HoTT 257
Napkin 228

The spec's 9.2M figure is from the paper; the live site now shows 8.4M.

  • Channels: a REST API at https://api.theoremsearch.com/search and MCP at https://api.theoremsearch.com/mcp. No terms of use are published.
  • Released data:
    • https://huggingface.co/datasets/uw-math-ai/theorem-search-dataset is tagged cc-by-sa-4.0, with 1,341,083 theorems from 209,777 papers. That matches the spec's 1.34M. It mixes Stacks (GFDL), ProofWiki and other sources under one BY-SA tag, which is a licence inconsistency (D4). Its card says "~15% of arXiv papers use permissive licenses (CC BY, CC BY-SA, or CC0)".
    • https://huggingface.co/datasets/uw-math-ai/theorem-search-dataset-permissive is tagged cc-by-4.0. Its card says 1,239,720 theorems from 197,889 papers (arXiv 1,238,975, Open Logic 745), covering CC0, CC BY 4.0, CC BY 3.0 and PD. ShareAlike is excluded. The dataset viewer shows 2,677,439 rows, which does not match the card (D5). The "slogans" (natural-language summaries) were written by DeepSeek-V3.1.
  • What math2 can take: the -permissive set as open candidate evidence (E1), keeping each row's per-paper licence. The BY-SA set should be used only after filtering out Stacks and any other GFDL or NC rows.

TheoremGraph and LeanGraph (https://arxiv.org/abs/2606.25363, 2026-06-24, cs.IR; the paper itself is under the arXiv non-exclusive licence)

  • https://huggingface.co/datasets/uw-math-ai/math-graph:
    • The card says CC BY 4.0, with "per-record reuse governed by each statement's source license". It has 16,131,238 rows.
    • The graph structure is open. Statement text is filled in only for CC0/BY/BY-SA papers and is NULL otherwise. paper_arxiv.csv has a licence column.
  • https://huggingface.co/datasets/uw-math-ai/theorem-matching has 101k rows, built from the Kaggle arXiv metadata.
  • What math2 can take: the edges and ids (CC BY 4.0, so attribute them), and text only where it is non-NULL. This is the best-licensed of the three big extractions.

Matlas (https://arxiv.org/abs/2604.17484, 2026-04-19; the paper is CC BY 4.0)

  • Size: 8.07M statements from 435K papers (1826–2025), 180 journals and 1.9K textbooks.
  • API: https://matlas.ai/openapi.json describes POST /api/search (num_results 10–200). It returns the statement text with doi, title, authors, journal, year and type. There is also /api/feedback.
  • No auth, no licence and no terms are published. The licence of the corpus is UNVERIFIED and probably not open. The statements are from journals and textbooks under copyright.
  • What math2 can take: under spec 9.6, query-time matching only, storing only DOIs and ids (record).

New 2026 projects not in spec 01

Project Date Licence What it is
uw-math-ai/FormalArXiv (https://huggingface.co/datasets/uw-math-ai/FormalArXiv) n/a "other" 89 Lean statements from August 2026 arXiv papers, via LemmaBench
Lean Pool (https://arxiv.org/abs/2609.25199, Ilin) 2026-09-21 paper CC BY 4.0 an AI-maintained archive of formalised mathematics
AnnalsChallenge (https://arxiv.org/abs/2610.18301, Buzzard et al.) 2026-10-13 paper CC BY-SA 4.0 50 Lean statements of Annals results
Stacks↔Mathlib alignment (https://arxiv.org/abs/2610.31011; code https://github.com/AnkitSatpute/Formal-Informal-Mathematical-Alignment) 2026-10-22 paper CC BY 4.0 added to MaRDI
KnowTeX (https://arxiv.org/abs/2601.15294) n/a n/a n/a
uw-math-ai other artefacts (https://huggingface.co/uw-math-ai: MELD, Math2Vec, APRIL, MathLeap models; https://github.com/uw-math-ai/arXiTeX) n/a no licences on the org page n/a

Part 2. Open textbooks

Licences were read at the book's own source (repository LICENSE, README or front matter) unless a row says "per OTL". In the Open Textbook Library (OTL), licences are sometimes stale; see §2.3.

2.1 Verified at source

Book Licence (exact) Format Repository / source URL 9.3 class
Univalent Foundations, Homotopy Type Theory (HoTT book) CC BY-SA 3.0 Unported LaTeX https://github.com/HoTT/book (README) open
Open Logic Project CC BY 4.0 LaTeX https://github.com/OpenLogicProject/OpenLogic open
Hefferon, Linear Algebra dual: GFDL or CC BY-SA 3.0 US, at the user's choice LaTeX https://hefferon.net/source.html, https://gitlab.com/jim.hefferon/linear-algebra open (take it under BY-SA)
Lebl, Basic Analysis I/II dual: CC BY-NC-SA 4.0 and CC BY-SA 4.0 LaTeX https://github.com/jirilebl/ra open (take it under BY-SA)
Lebl, Notes on Diffy Qs dual: CC BY-NC-SA 4.0 and CC BY-SA 4.0 LaTeX https://github.com/jirilebl/diffyqs open (BY-SA)
Lebl, Tasty Bits of Several Complex Variables dual: CC BY-NC-SA 4.0 and CC BY-SA 4.0 LaTeX https://github.com/jirilebl/scv open (BY-SA)
Boelkins et al., Active Calculus (single variable, 2012–2025 edition) CC BY-SA 4.0 PreTeXt https://github.com/active-calculus/active-calculus-single-mbx (source/bibinfo.xml) open
Evan Chen, An Infinitely Large Napkin text CC BY-SA 4.0; source code GPL v3 LaTeX https://github.com/vEnhance/napkin/ open (text)
Levin, Discrete Mathematics: An Open Introduction, 3rd edition and earlier CC BY-SA 4.0 PreTeXt https://github.com/oscarlevin/discrete-book open
Levin, same book, 4th edition CC BY-NC-SA 4.0 PreTeXt same share-alike-nc
Keller and Trotter, Applied Combinatorics CC BY-SA 4.0 PreTeXt https://github.com/mitchkeller/applied-combinatorics open
Ernst, An Introduction to Proof via Inquiry-Based Learning CC BY-SA 4.0 LaTeX https://github.com/dcernst/IBL-IntroToProof open
Austin, Understanding Linear Algebra CC BY 4.0 (licence link in README) PreTeXt https://github.com/davidaustinm/ula open
Beck, Marchesi, Pixton, Sabalka, A First Course in Complex Analysis v1.6 CC BY 4.0 PDF (LaTeX not checked) https://matthbeck.github.io/complex.html open
Lehman, Leighton, Meyer, Mathematics for Computer Science (2018 rev.) CC BY-SA 3.0 ("available under the terms of the Creative Commons Attribution-ShareAlike 3.0 license") PDF https://courses.csail.mit.edu/6.042/spring18/mcs.pdf open
Judson, Abstract Algebra: Theory and Applications (AATA) GFDL 1.3 or later PreTeXt https://github.com/twjudson/aata gfdl
Beezer, A First Course in Linear Algebra (FCLA) GFDL 1.2 or later PreTeXt https://github.com/rbeezer/fcla gfdl
The Stacks Project GFDL 1.2 LaTeX https://stacks.math.columbia.edu (COPYING) gfdl
Hartman et al., APEX Calculus CC BY-NC 4.0, © 2021 Hartman PreTeXt https://github.com/APEXCalculus/APEXCalculusPTX (ptx/apex.ptx) share-alike-nc
Feldman, Rechnitzer, Yeager, CLP Calculus (UBC) CC BY-NC-SA 4.0 ("It is licensed under a Creative Commons BY-NC-SA 4.0 International License") LaTeX source published https://personal.math.ubc.ca/~CLP/src/ share-alike-nc
Axler, Linear Algebra Done Right, 4th edition CC BY-NC 4.0 (Springer open access) PDF; HTML via PreTeXt (David Farmer) https://link.springer.com/book/10.1007/978-3-031-41026-0, https://library.oapen.org/handle/20.500.12657/85067, https://linear.axler.net/ (PDF dated 2026-08-16), https://ladr.pretext.plus/ share-alike-nc
Hammack, Book of Proof, 3rd edition (v3.4, 2025-02-05) CC BY-NC-ND 4.0 PDF only https://richardhammack.github.io/BookOfProof/ verbatim
Hatcher, Algebraic Topology not a CC licence: "Single paper or electronic copies for noncommercial use may be made freely without explicit permission from the author or publisher" (© 2002 CUP) PDF https://pi.math.cornell.edu/~hatcher/AT/ATpage.html record
Lurie, Kerodon no licence statement found anywhere on the site (about page: maintained by Jacob Lurie, built on Gerby). /statistics shows 8,189 tags web (Gerby) https://kerodon.net/ record (all rights reserved by default). This contradicts spec 9.3 and 16.6, which call it GFDL (D6)

2.2 OpenStax mathematics

Licences were read from each book's collection.xml md:license on GitHub (the openstax/osbooks-* repositories). openstax.org/subjects/math returned an empty page.

Book (OpenStax repository) Licence 9.3 class
Calculus Vols 1–3, College Algebra 2e, Precalculus 2e, Algebra and Trigonometry 2e, Prealgebra 2e, Elementary Algebra 2e, Intermediate Algebra 2e, Introductory Statistics 2e, Introductory Business Statistics 2e, Contemporary Mathematics, Algebra 1, Principles of Data Science, Cálculo (Spanish) CC BY-NC-SA 4.0 share-alike-nc
osbooks-statistics (Statistics), Precálculo 2ed CC BY 4.0 open

Earlier editions were CC BY: the OTL lists Prealgebra 2e (2015), Precalculus (2014) and Introductory Statistics 2e (2023) as BY. Earlier CC BY editions are still CC BY, and math2 could adapt those editions specifically (D7).

2.3 Aggregators and catalogues

Open Textbook Library (https://open.umn.edu/opentextbooks/subjects/mathematics.json)

  • total_count is 214; 191 entries were retrieved. Licence counts:
Licence Books
BY-NC-SA 67
BY 51
BY-SA 38
BY-NC 17
GFDL 12
BY-NC-ND 3
"No Rights Reserved" 2
BY-ND 1
  • So about 48% are open (BY, BY-SA, CC0) and 52% are not.
  • The subject also contains some non-mathematics books (statistics, psychology).
  • OTL licences can be stale or simplified. It lists Active Calculus 2.0 (2017) as BY-NC-SA, while the current edition is BY-SA. It lists Book of Proof as "Attribution-NoDerivs", while the author's page says BY-NC-ND. It lists Hefferon as BY-SA only, while the book is dual-licensed GFDL / BY-SA. Verify at source before ingesting.

American Institute of Mathematics (AIM) Open Textbook Initiative, approved list (https://textbooks.aimath.org/textbooks/approved-textbooks/)

  • 68 unique titles grouped by course. Licences are not shown on the list. The verified licences for AIM titles are in §2.1, §2.5 and §2.6.
  • AIM titles not otherwise covered in this note include Bruckner–Thomson, ORCCA, Manes, May–Bart, Marsden–Weinstein, Boyd–Vandenberghe, Treil, Fields, Bender–Williamson, Bard, Zimmermann, Crisman, Stein and Connell. Their licences were not checked (D11).

PreTeXt catalogue (https://pretextbook.org/catalog.html)

  • 80 projects, 67 of them mathematics.
  • GFDL badges: FCLA, Discover Linear Algebra, Fitch Discrete Math, Yoshiwara Elementary Algebra, LA Companion, LA Refresher, Yoshiwara Modeling, Functions and Graphs, Yoshiwara Trigonometry, AATA, AA Refresher, IBL Geometries, Exploring Combinatorial Mathematics, First-Semester Abstract Algebra, Hitchman Geometry with an Introduction to Cosmic Topology, Models of Non-Euclidean Geometry, The ODE Project, Algebraic Graph Theory with Sage, Elementary Foundations, A Second Course in Linear Algebra, Abstract Algebra for Teachers, Cryptology.
  • All rights reserved: Linear Algebra (W214) and Intro to Topology (IBL).
  • The rest are badged only "Creative Commons", without saying which variant. Each needs a source check.

LibreTexts (https://math.libretexts.org/Bookshelves)

  • The licence is set per page, through tags such as license:ccbyncsa and an auto-generated "Detailed Licensing" back-matter page. An example: https://math.libretexts.org/Bookshelves/Calculus/Calculus_(Guichard)/00%3A_Front_Matter/04%3A_Licensing.
  • Many pages are "not declared". The licence mix inside a single book is common.
  • The terms (https://libretexts.org/terms-conditions, effective 2020-10-15) allow copying of open-licensed content as its licence permits. They have no AI or scraping clause.
  • There are no aggregate licence statistics, so the mix is UNVERIFIED.
  • For math2: go to the upstream source of each LibreTexts book, not the LibreTexts copy. Use LibreTexts only page by page, by the page's license: tag. "Not declared" counts as record.

MIT OpenCourseWare (https://ocw.mit.edu/pages/privacy-and-terms-of-use/)

  • Course materials are CC BY-NC-SA 4.0, so share-alike-nc.
  • There is a "Permitted Use of AI Training" section: training is allowed with attribution, the models must be non-commercial, and derivative models must be released under BY-NC-SA.
  • There is no bulk-download section.
  • A note: MIT 6.042's Mathematics for Computer Science is distributed separately under CC BY-SA 3.0 (§2.1), so it is open, unlike the OCW course pages.

2.4 Books commonly assumed open that are not

Book Status
Hatcher, Algebraic Topology noncommercial copying only; record
Book of Proof ND, so verbatim
Axler LADR4 NC
APEX NC
CLP NC-SA
OpenStax 2e math editions NC-SA
Kerodon no licence; record

2.5 Table A: textbooks math2 may adapt into CC BY-SA 4.0 node prose (CC0, CC BY, CC BY-SA)

Attribution is required for all of them. CC BY-SA 3.0 (Unported or US) adaptations may be licensed under BY-SA 4.0: CC BY-SA 3.0 Unported §4(b) (https://creativecommons.org/licenses/by-sa/3.0/legalcode.en, read 2026-10-26) allows an adaptation to be distributed under "a later version of this License with the same License Elements". I did not re-read the 3.0 US port; I assume it has the same clause, which matters for Hefferon. Treat that as UNVERIFIED.

Book Licence math2 uses Source format Repository / URL Notes
Open Logic Project CC BY 4.0 LaTeX https://github.com/OpenLogicProject/OpenLogic already in TheoremSearch (588 / 745 items)
HoTT book CC BY-SA 3.0 → 4.0 LaTeX https://github.com/HoTT/book
Hefferon, Linear Algebra CC BY-SA 3.0 US option of the dual licence LaTeX https://gitlab.com/jim.hefferon/linear-algebra record that math2 elected the BY-SA option
Lebl, Basic Analysis I/II CC BY-SA 4.0 option of the dual licence LaTeX https://github.com/jirilebl/ra elect BY-SA
Lebl, Notes on Diffy Qs CC BY-SA 4.0 option LaTeX https://github.com/jirilebl/diffyqs elect BY-SA
Lebl, Tasty Bits of SCV CC BY-SA 4.0 option LaTeX https://github.com/jirilebl/scv elect BY-SA
Active Calculus (single variable, 2012–2025) CC BY-SA 4.0 PreTeXt https://github.com/active-calculus/active-calculus-single-mbx the OTL's "BY-NC-SA" is for 2.0 (2017) and is stale
Napkin (text) CC BY-SA 4.0 LaTeX https://github.com/vEnhance/napkin/ do not take the GPL code
Levin, Discrete Mathematics, 3rd edition and earlier CC BY-SA 4.0 PreTeXt https://github.com/oscarlevin/discrete-book pin a pre-4th-edition commit or tag
Keller–Trotter, Applied Combinatorics CC BY-SA 4.0 PreTeXt https://github.com/mitchkeller/applied-combinatorics
Ernst, Intro to Proof via IBL CC BY-SA 4.0 LaTeX https://github.com/dcernst/IBL-IntroToProof
Austin, Understanding Linear Algebra CC BY 4.0 PreTeXt https://github.com/davidaustinm/ula
Beck et al., First Course in Complex Analysis CC BY 4.0 PDF https://matthbeck.github.io/complex.html
Lehman–Leighton–Meyer, Mathematics for Computer Science CC BY-SA 3.0 → 4.0 PDF https://courses.csail.mit.edu/6.042/spring18/mcs.pdf
OpenStax Statistics, Precálculo 2ed, and the earlier CC BY editions (Prealgebra 2015, Precalculus 2014) CC BY 4.0 CNXML github.com/openstax (osbooks-statistics and others) pin the CC BY edition
Per OTL, not verified at source: Zakon, Mathematical Analysis I; Counting Rocks!; Calculus in Context; Kuttler, A First Course in Linear Algebra; Shimamoto, Multivariable Calculus; Dumas–McCarthy; Wiggins, ODE CC BY various https://open.umn.edu/opentextbooks/subjects/mathematics.json verify at source (D8)
Per OTL, not verified at source: Kuttler, Linear Algebra, Theory and Applications; Hitchman (OTL says BY-SA, but the PreTeXt catalogue shows GFDL, D8); Petrunin, Euclidean Plane and its Relatives; Callahan, Euclid's Elements Redux; Davies, A Cool Brisk Walk; Brin, Tea Time Numerical Analysis and Tea Time Linear Algebra; Lippman, Math in Society; OpenIntro Statistics; Introduction to Modern Statistics 2e CC BY-SA various same verify at source
Public domain (US, pre-1931): e.g. Hardy, A Course of Pure Mathematics (PG #38769); Dedekind; Casey's Euclid; Thompson, Calculus Made Easy public domain (US) LaTeX / HTML https://www.gutenberg.org/ebooks/bookshelf/102 strip PG trademark text; check non-US status

2.6 Table B: textbooks math2 may NOT adapt into node prose (NC, ND, GFDL, all rights reserved)

All of these can still give records, locators, tables of contents (9.7) and internal embeddings.

Book Licence 9.3 class URL
Judson, AATA GFDL 1.3+ gfdl https://github.com/twjudson/aata
Beezer, FCLA GFDL 1.2+ gfdl https://github.com/rbeezer/fcla
Stacks Project GFDL 1.2 gfdl https://stacks.math.columbia.edu
The PreTeXt GFDL-badged titles (§2.3: Yoshiwara ×3, Fitch, ODE Project, etc.) GFDL gfdl https://pretextbook.org/catalog.html
Per OTL: Grinstead–Snell, Introduction to Probability; Bogart, Combinatorics Through Guided Discovery; Corral, Vector Calculus and others; Collingwood et al., Precalculus; Yoshiwara, Modeling (12 GFDL in total) GFDL gfdl https://open.umn.edu/opentextbooks/subjects/mathematics.json
Hartman et al., APEX Calculus CC BY-NC 4.0 share-alike-nc https://github.com/APEXCalculus/APEXCalculusPTX
Axler, LADR 4e CC BY-NC 4.0 share-alike-nc https://link.springer.com/book/10.1007/978-3-031-41026-0
Per OTL: Axler, Measure, Integration & Real Analysis; Lafferriere et al. CC BY-NC share-alike-nc OTL
CLP Calculus (UBC) CC BY-NC-SA 4.0 share-alike-nc https://personal.math.ubc.ca/~CLP/src/
Levin, Discrete Mathematics, 4th edition CC BY-NC-SA 4.0 share-alike-nc https://github.com/oscarlevin/discrete-book
OpenStax Calculus 1–3, College Algebra 2e, Precalculus 2e, Algebra & Trig 2e, Prealgebra 2e, Elementary/Intermediate Algebra 2e, Intro Statistics 2e, Business Stats 2e, Contemporary Math, Algebra 1, Principles of Data Science, Cálculo CC BY-NC-SA 4.0 share-alike-nc github.com/openstax
MIT OCW course materials CC BY-NC-SA 4.0 (AI-training clause: non-commercial, BY-NC-SA models) share-alike-nc https://ocw.mit.edu/pages/privacy-and-terms-of-use/
Per OTL: Guichard, Calculus (early transcendentals); Trench, Introduction to Real Analysis and Elementary Differential Equations; Sundstrom, Mathematical Reasoning; Doerr–Levasseur, Applied Discrete Structures; Rogers–Boman; Stitz–Zeager; Cherney et al., Linear Algebra; Nicholson, Linear Algebra with Applications; Morris, Proofs and Concepts; Sloughter; Hill–Thron; Strang, Calculus CC BY-NC-SA share-alike-nc OTL
Hammack, Book of Proof 3e CC BY-NC-ND 4.0 verbatim https://richardhammack.github.io/BookOfProof/
Per OTL: Shoup, A Computational Introduction to Number Theory and Algebra CC BY-NC-ND verbatim OTL
Hatcher, Algebraic Topology © CUP 2002; noncommercial copies only record https://pi.math.cornell.edu/~hatcher/AT/ATpage.html
Lurie, Kerodon no licence stated, so all rights reserved record https://kerodon.net/
PreTeXt: Linear Algebra (W214), Intro to Topology (IBL) all rights reserved record https://pretextbook.org/catalog.html
LibreTexts pages tagged "not declared" none record https://math.libretexts.org

Part 3. Syllabi and theorem lists

3.1 MAA CUPM Curriculum Guide (2015)

  • Citation: 2015 CUPM Curriculum Guide to Majors in the Mathematical Sciences, Schumacher and Siegel (co-chairs), Zorn (editor). 116 pages. The PDF has CreationDate 2015-05-05.
  • Copyright: "© 2015 The Mathematical Association of America (Incorporated)", ISBN 978-0-88385-917-9. I found no CC licence, so it is record.
  • URLs:
    • Official page: https://maa.org/resource/cupm-guide/. It is JavaScript-rendered, so curl got no content.
    • Copy I read: https://www.amstat.org/docs/default-source/amstat-documents/cupmguide_print.pdf
    • The separate course-area reports (Abstract Algebra, Real Analysis, Topology, etc.) are linked from the MAA page. Their licences are not checked.
  • What math2 can take: the structure (course areas, topic lists) as facts for topics/curricula/, and citations. Not the prose.
  • Nothing newer than the 2015 guide was found (D12).

3.2 QAA Subject Benchmark Statement: Mathematics, Statistics and Operational Research

  • Current edition: the 5th edition, published 2023-03-08 (the PDF's last page reads "Fifth Edition / Published - 8 March 2023"). It covers Master's level too.
  • Page: https://www.qaa.ac.uk/the-quality-code/subject-benchmark-statements/subject-benchmark-statement-mathematics-statistics-and-operational-research
  • PDF: https://www.qaa.ac.uk/docs/qaa/sbs/sbs-mathematics-statistics-and-operational-research-23.pdf, 2.1 MB, 35 pages.
  • Copyright: "© The Quality Assurance Agency for Higher Education 2023". No CC or OGL licence is stated in the PDF, so it is record. (An older 2009 annex is in DERA under the Open Government Licence. That does not carry over to 2023.)
  • Upcoming: the QAA site has a "Subject Benchmark Statement Reviews 2026-27" page, so a 6th edition may be in progress (D12).
  • What math2 can take: its outcome categories, as facts.

3.3 Mathlib lists

Source: leanprover-community/mathlib4 master (repository HEAD 4c30f23495 at 2026-10-26T08:02Z). Licence Apache-2.0.

File Contents Last change
docs/undergrad.yaml (https://raw.githubusercontent.com/leanprover-community/mathlib4/master/docs/undergrad.yaml) 563 leaf items, 130 of them empty (not yet formalised). The topics were originally taken from the 2020 French agrégation programme 58d1b21e88, 2026-10-07
docs/overview.yaml 511 leaves n/a
docs/1000.yaml 1,199 entries keyed by Wikidata id; 217 have decl(s), 30 have an external url c6f03d20ca, 2026-10-17
docs/100.yaml 100 entries; 78 have decl n/a

What math2 can take: everything. These are Apache-2.0 code-zone data and facts, and the best machine-readable syllabus and theorem lists available. The Wikidata keys of 1000.yaml are crosswalk ids.

3.4 Freek Wiedijk's 100 theorems

  • Page: https://www.cs.ru.nl/~freek/100/, last modified 2026-09-17. All 100 theorems are formalised in at least one system.
  • Per system:
System Theorems
HOL Light 95
Isabelle 95
Lean 83
Rocq 80
Metamath 74
Mizar 71
ACL2 48
ProofPower 43
PVS 26
Imandra 20
Megalodon 12
Naproche 10
NuPRL 8
  • Licence: no licence statement, so record. The list of theorem names is factual.
  • Discrepancy: Mathlib's 100.yaml has 78 entries with a decl, but Freek's page counts 83 for Lean. The difference is probably entries proved outside Mathlib, or stale yaml. Not resolved.

3.5 The 1000+ theorems project

  • Site: https://1000-plus.github.io/. I counted 228 entries on the page.
  • Repository: https://github.com/1000-plus-theorems/1000-plus, licence Unlicense, last pushed 2026-07-22. That makes it public-domain-equivalent, so open.
  • Relation to Mathlib: Mathlib's 1000.yaml is the Lean-side view of the same Wikidata-keyed list.

3.6 Department qualifying-exam lists

  • Example: UC Berkeley Preliminary Examination (https://math.berkeley.edu/graduate/phd-program/preliminary-exam).
    • Two mornings of 3 hours each. Students attempt 5 of 8 questions per day (9 before Fall 2024).
    • Topics: real analysis and calculus, complex analysis, linear algebra, abstract algebra.
    • The syllabus PDF and past exams are linked at the bottom of the page.
  • These are department web pages with no licence, so record. Topic lists are factual. Past exam problems are copyrighted text.
  • Berkeley Problems in Mathematics (de Souza and Silva, Springer) collects 1,250 prelim problems from 1977 to 2003. It is all rights reserved.
  • I did not survey other departments; other examples include UW (https://math.washington.edu/phd-preliminary-exams). Breadth is UNVERIFIED (D12).

Summary table

Item Size (date) Licence of text / data Format Bulk channel and terms AI terms What math2 can take (9.3)
arXiv about 9.2 TB of files (April 2025), +100 GB/month metadata CC0; text per paper. 2026 math sample is 36.9% open (BY/BY-SA/CC0) vs 15% all-time TeX source, PDF s3://arxiv requester-pays; API 1 req / 3 s; must link back; redistributing e-prints needs the holder's permission none stated records (CC0); text of open papers into prose; others record
zbMATH Open 4M+ publications, 3M+ reviews, 168M+ triples (KG v1, 2026-09-01); 133,093 documents for 2025 KG: Zenodo field CC BY 4.0 vs description CC BY-SA 4.0; I4OC references CC0 RDF/TTL, JSON API, OAI-PMH Zenodo dump (1.6 GB, twice a year); REST; OAI-PMH; API terms UNVERIFIED UNVERIFIED records, MSC, reviews as open evidence
OpenAlex about 745 GB JSONL (September 2026) CC0 JSONL, Parquet s3://openalex anonymous, quarterly; API key since 2026-02 (secondary source) none all metadata
Unpaywall n/a n/a n/a folded into OpenAlex; data feed paid; terms UNVERIFIED n/a OA locations via OpenAlex
Crossref 180,034,490 records, 208 GB (2026-03-14) metadata effectively free; some abstracts copyrighted JSONL public data file (torrent, AWS); open REST API none metadata, references; abstracts record
DataCite 108M DOIs (2025 file, 2026-01-06) CC0 JSON annual public file; monthly file members-only none all metadata
Semantic Scholar / S2ORC S2ORC 15,679,781 full texts (2026-05-26) API non-transferable; S2ORC ODC-By (database) plus per-paper copyright; abstracts UNVERIFIED JSON API key; Datasets API none ids; text only per paper licence
CORE 291M metadata / 32.8M full texts (2023); current size UNVERIFIED dumps ODC-By (database only) JSON API licence; dumps proposed "lawful TDM" records; text per paper
HAL (math) 170,406 records, 105,413 with file (2026-10-26) metadata CC0; files: 9.8% open, 80% hal-authorisation PDF, TEI OAI-PMH, REST, SPARQL none found records; the 10,349 open texts
Numdam 75,599 articles, 706 books, 1.43M pages metadata CC0; text: personal use, no bulk, no modification PDF, OAI OAI-PMH (metadata only) none records; text only where CC or PD
EuDML over 270k documents (undated) UNVERIFIED n/a blocked (403) n/a records via partner sources
Project Euclid "over 80%" free to read per journal, UNVERIFIED PDF none found n/a records; per-article licence
GDZ over 15M pages scans' licence UNVERIFIED; PDFs: no re-hosting without permission IIIF, PDF IIIF, OAI n/a records; public-domain statements rewritten
HathiTrust n/a public-domain subsets; terms UNVERIFIED (Cloudflare) text ht_text_pd* datasets UNVERIFIED US pre-1931 public-domain text
Internet Archive 206,597 math texts; 8,076 dated 1500–1930 mixed; hosting does not establish licence PDF, OCR advancedsearch; terms UNVERIFIED UNVERIFIED public-domain items after a per-item check
Project Gutenberg about 78,000 items (2026-03) public domain (US) TXT, HTML, some LaTeX mirrors or /robot/harvest, -w 2 none open (strip PG trademark)
TheoremSearch 8.4M indexed (live site); 1,341,083 BY-SA release; 1,239,720 permissive release HF tags BY-SA / BY; BY-SA set includes GFDL Stacks Parquet, REST, MCP Hugging Face; API with no terms none -permissive set as E1 candidates
TheoremGraph / LeanGraph 16,131,238 rows (math-graph) CC BY 4.0 plus per-record source licence; text NULL unless open CSV, Parquet Hugging Face none edges, ids, open-only text
Matlas 8.07M statements, 435K papers, 1.9K textbooks not stated (UNVERIFIED; likely closed) JSON API POST /api/search, no terms none query-time ids only (record)
Open textbooks 214 math books in OTL; 68 AIM-approved; 67 PreTeXt math OTL: 48% open, 52% NC/ND/GFDL LaTeX, PreTeXt, PDF Git repositories MIT OCW: NC models only Table A only
MIT OCW n/a CC BY-NC-SA 4.0 HTML, PDF none training allowed, NC models, BY-NC-SA share-alike-nc
CUPM 2015 116 pages © MAA PDF n/a n/a structure as facts
QAA SBS MSOR (5th edition, 2023-03-08) 35 pages © QAA 2023 PDF n/a n/a structure as facts
Mathlib yaml undergrad 563 (130 empty); 1000.yaml 1,199; 100.yaml 100 Apache-2.0 YAML Git n/a all
Freek's 100 100 (2026-09-17) no licence HTML n/a n/a list as facts
1000+ theorems 228 entries on the site Unlicense Markdown, YAML Git n/a all

Open doubts

  1. D1. zbMATH KG licence. The Zenodo field says CC BY 4.0, but the record description says CC BY-SA 4.0. Ask zbMATH (or open a GitHub issue on zbMATHOpen/zbmath-open-kg) which one governs. Both are open, but BY-SA binds derived exports. The API terms are unread (Cloudflare).
  2. D2. arXiv open share. The spec's "about 15%" is the all-time stock. My three-day 2026 math sample gives 36.9% (and about 39% for re-versioned older papers). Confirm this with a full 2026 set=math harvest from the tamnd/arxiv metadata plane. Separate first versions from updates, and decide whether cross-lists count. If it holds, spec 9.3 should state both figures.
  3. D3. Missing AI clauses. arXiv, Crossref, OpenAlex, HAL and Gutenberg say nothing about AI. MIT OCW has an explicit NC-only AI clause. Stack Exchange forbids LLM use (already in the spec). The zbMATH, HathiTrust, IA and EuDML terms are unread. Silence in the terms is not permission: the per-item licence still governs.
  4. D4. TheoremSearch BY-SA set puts Stacks (GFDL), ProofWiki and other sources under one cc-by-sa-4.0 tag. math2 must filter by source and licence before treating any row as open.
  5. D5. TheoremSearch counts. The card says 1,239,720 rows for the permissive set; the dataset viewer shows 2,677,439 rows. The BY-SA set has 1,341,083. The live site shows 8.4M against the paper's 9.2M. Not reconciled. The difference may be duplicated rows across splits, or slogans stored as separate rows.
  6. D6. Kerodon licence. Spec 9.3 and 16.6 list Kerodon as GFDL; I found no licence statement anywhere on kerodon.net. Unless Lurie states a licence, Kerodon is all rights reserved, so record. The spec should change it to record, and §1.7's "[U]" should be resolved accordingly. The tag count on /statistics is 8,189; §1.7 says "2,200+ pages".
  7. D7. OpenStax edition drift. The current 2e repositories are CC BY-NC-SA 4.0, but older editions were CC BY. Adapting an old CC BY edition is legal, but the edition and commit must be pinned.
  8. D8. OTL licences are stale or simplified (Active Calculus, Book of Proof, Hefferon, Hitchman). Every Table A row marked "per OTL" must be verified at the source before ingestion.
  9. D9. Dual-licensed books (Lebl ×3, Hefferon). math2 must record its election of the BY-SA option in the source entry.
  10. D10. Public domain is territorial. The US pre-1931 rule does not make a work public domain elsewhere (life plus 70 years in the EU). Since math2 is published worldwide, decide whether US public domain is enough for open. For Hardy (died 1947) the text is public domain in the EU too; for some authors it is not.
  11. D11. AIM titles with unchecked licences (Bruckner–Thomson, ORCCA, Manes, May–Bart, Marsden–Weinstein, Boyd–Vandenberghe, Treil, Fields, Bender–Williamson, Bard, Zimmermann et al., Crisman, Stein, Connell).
  12. D12. Syllabi.
    • CUPM 2015 is the latest guide I found; I did not confirm whether a newer one exists.
    • The QAA 6th-edition review (2026–27) has not been checked.
    • Qualifying-exam lists were sampled at one department only.
    • The difference between Mathlib's 100.yaml (78 with decl) and Freek's Lean count (83) is not resolved.
  13. D13. UNVERIFIED because of blocking or missing pages:
    • zbMATH API terms
    • EuDML metadata licence and size
    • HathiTrust terms
    • Internet Archive terms
    • current CORE size and dump terms
    • Unpaywall terms
    • Semantic Scholar abstracts licence
    • Project Euclid per-journal licences
    • GDZ scan licence
    • OpenAlex API pricing (secondary source only)
  14. D14. Matlas returns full statement text from copyrighted journals and textbooks through an open API with no terms. math2 should store only ids from it (spec 9.6). Its corpus licence is unknown.
  15. D15. LibreTexts has no aggregate licence data. The per-page "not declared" share is unknown; treat it as record and prefer the upstream source.

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