Terms of Service#

Last updated: 29 October 2023

Alpine Mathematics (“we”, “us”, “our”) is a non-profit organization dedicated to promoting the accessibility and appreciation of mathematics and its history. These Terms of Service (“Terms”) let you know what you can expect of us, and what we expect of you, when you use PISE Online (the “Site”, or the “Service”).

The nature of our services#

The purpose of this section is to make clear what PISE Online is, and what type of service Alpine Mathematics is offering, as its operator. This section also introduces key terms.

PISE Online is essentially a browsing, indexing, and note recording service. We explain what these terms mean below.

Our Service is not essentially about making content available, because any content you load through our Service must already be available in the form of a code repository hosted at GitHub, BitBucket, or another such provider (hereinafter, “Code Repository Hosting Provider” or “CRHP”). We receive and distribute the content under the same license under which it is offered as a code repository.

Instead, our Service is about helping you study such content.

Specifically, the content you study at our Site comes from Proofscape repositories (“repos”). The code in these repos is written in the Proofscape language, and defines two types of entities, called Deductions (diagrams of mathematical proofs) and Annotations (textual discussion and commentary on the proofs). Collectively, we refer to Deductions and Annotations as “Articles”.

The Proofscape language also defines a feature called a Goal Box. An Article may contain any number of Goal Boxes, each of which represents a study goal. When browsing an Article, you can place a checkmark on a Goal Box in order to signify to yourself that you have reached the goal it represents. You can also record free-form notes on a Goal Box, such as to remind yourself of some ideas or questions associated with the goal. We refer to your collection of check marks and free-form notes as your “Study Notes”.

The main components of our Service then are:

  • Browsing: Through the Site, you can load Articles from Proofscape repos. You are able to load both the textual and graphical displays they generate, and their source code form.

  • Indexing: We maintain a database of links between Articles, and we enrich the Articles with these links. Linked Articles may belong to the same or different repos. This makes it so that, for example, when browsing a Deduction diagram, you can easily discover that there is an Annotation that talks about this Deduction, or that there is another Deduction that expands on the first one. You are then able to easily load and browse the linked Articles.

    • Indexing-by-Request: As a subservice of our indexing Service, we offer logged-in users of our Site the ability to lodge a formal request that we index one of their own Proofscape repos. If you make an indexing request, and we grant your request, this has the effect of adding links to our database, so that anyone browsing Articles at our Site may easily discover links to and from your repo.

  • Note Recording: We offer an optional service called Server-Side Note Recording (SSNR). If you log into our Site, you may then opt into the SSNR service. When SSNR is activated, your Study Notes are recorded for you in our database. This makes it so that the next time you return to an Article, your notes and checkmarks are restored to the state in which you left them (provided you are logged into the same account).

A note about sign-ins#

Sign-ins (or log-ins) to PISE Online are always mediated by an OAuth provider, (“OAuth Provider” or “OAP”) which must also be a Code Repository Hosting Provider. GitHub is an example of such a provider, and from time to time we may extend (or in extremely rare cases shorten) the list of providers we support.

Providing us with an OAuth log-in from a CRHP is how you prove to us that you own certain code repositories. We use this information to help us decide whether to allow you to take certain actions relative to these repositories, at our Site.

Age restriction#

You must be at least 13 years old to use the Services.

Privacy policy#

We ask that you review the terms of our Privacy Policy, so that you are aware of how we collect and use your information. Because our Site is available all over the world, while our infrastructure operates in data centers located in the United States, by using our services you consent to the processing of your data in the United States.

Safety and executable code#

Proofscape modules contain executable code. When you decide to load a Proofscape module in your browser, you should understand that this is the same as downloading software from the Internet, and running it on your computer.

It is therefore important to proceed with caution, and exercise judgment. Just as you would only run software from authors you trust, you should only load Proofscape modules from authors you trust.

See our Disclaimers and Limitation on liability later in these Terms.


All Proofscape repos hosted by the Site are licensed under the Mozilla Public License, version 2.0 (MPL-2.0). You can find the full text of the license at the Mozilla Foundation’s website, and you may also find their FAQ helpful.

Accordingly, if you would like us to consider hosting one of your own Proofscape repos, it is a prerequisite that you license your work under the MPL-2.0. We have written our own FAQ, explaining such things as why we chose the MPL-2.0 for this purpose, and how you can apply the license to your Proofscape content repos.

Indexing requests#

Through the Site, you can lodge a request for us to index a Proofscape repo owned by you, thereby making it easier for others to discover your work while browsing content at PISE Online.

We want this to be a welcoming process, and, generally speaking, we do not intend to place high barriers to acceptance. That being said, we do have to maintain certain rules, for the benefit of everyone who uses the Site.

  • On-topic: We only accept material about mathematics.

  • Properly and legally licensed: As explained in the section above on Licensing, we only accept repos that are licensed under MPL-2.0. Furthermore, if you request indexing of a Proofscape repo, you represent that either you are the author of the material, or that you otherwise have the legal right to so license it.

  • No malware: If you request indexing of a Proofscape repo, you attest that, to your knowledge, it does not contain malware.

  • Non-offensive: We will not accept any material containing offensive or obscene content (to be determined in our sole discretion).

  • Acceptable names only: Every object in a Proofscape module has a unique address, called a library path, or “libpath”. Each libpath begins with the host, user, and repo segments, which correspond to the names of your OAuth provider, your username with them, and the name of your repo with them.

    Because libpaths appear throughout modules, your username and the name of your repo therefore become a part of the content you submit. For this reason, we may have to reject content due to usernames or repo names which can potentially be unacceptable for a number of reasons, such as: being obscene or offensive, or giving a false impression of being somehow officially associated with Alpine Mathematics.

  • Our decision: Ultimately it is up to us whether we accept any given request or not.

Server-Side Note Recording#

We hope that the Server-Side Note Recording (SSNR) feature of our Site (see above) will be useful to you. It is intended as a handy way to keep your Study Notes available to you upon log-in, (a) no matter which device you may use to connect to our Site, and (b) even if you clear local storage from your browser.

SSNR is strictly an opt-in service. It is not available to you at all unless you log in, and, even after logging in, it is not active until you choose to activate it. You can pause the service at any time. Merely pausing SSNR does not cause us to delete your Notes. If and when you re-activate SSNR, your Notes should still be as you left them. If you want us to delete all Notes recorded through SSNR, you can request this through the user settings dialog in PISE Online. See also our Privacy Policy.

SSNR is also strictly an “as available” service. This means that, while we will make our best effort to keep the service available, we do not make any actual guarantees of uptime or availability. We ask you to remember that PISE Online is a free service, which we offer to the best of our ability.

In order for us to maintain the SSNR service as a free and useful tool for everyone, we require you to make certain agreements:

  • You agree to use SSNR only for its intended purpose, which is: the jotting down of brief notes, to aid in your study of mathematics. You understand that, if we become aware of, or have cause to suspect, your using SSNR for any purpose other than the intended one, we may deny you any further use of the Service. We may take gross measurements related to your Notes, for the purpose of detecting and preventing abuse of the Service. This may include, without limitation, measurement of the size of your Notes, individually or in aggregate, and measurement of the rate at which you record and/or update Notes.

  • Your Notes are intended, and designed, to be seen only by you. However, you agree not to use SSNR to record any ideas you wish to keep secret. This may include, without limitation, ideas for proving new theorems, or writing new proofs of old theorems. You agree not to record trade secrets, or any other information whose accidental exposure in the unlikely event of a data breach would cause you to consider seeking damages. You agree that under no circumstances will we be liable to you for any exposure of your ideas, loss of competitive advantage, or loss of the ability to be credited with an idea.

  • You accept that the amount of storage space available to you for SSNR may change. While we will try to give you fair warning, well in advance of any decrease in available storage, we are not required to do so, and may make these changes at any time. We reserve the right to set limits not only on storage space used overall, but on other parameters such as storage space used per note, frequency of updates to notes, and more. We reserve the right to stop providing the service altogether, to all users or to particular users, at our sole discretion.

  • You understand that, while we intend to employ industry standard practices to prevent data loss, no database system is perfect. You agree that under no circumstances will we be liable to you for any loss of data.

These agreements are intended to clarify what you can expect with the SSNR service, and what we require of you. More broadly, see the sections on Termination, Disclaimers, and Limitation on liability later in these Terms.


It is important that at Alpine Mathematics we protect our trademark rights so that we can protect our users from fraudulent impersonators. Because of this, we ask that you please respect our trademarks. All Alpine Mathematics trademarks belong to Alpine Mathematics. Without limiting our rights and remedies at law, any use of our trade names, trademarks, service marks, logos, or domain names must be in compliance with these Terms of Service and in compliance with the following rules:

  • You MAY use the marks in order to refer accurately to or link to our Site.

  • You may NOT use the marks to link to or label sites or projects we do not own or operate, to create mimicking websites or projects, or to otherwise mislead others.

  • You may not use the marks in any way not expressly permitted in these Terms, unless you have separately received express written permission from us to do so. If you would like to use the marks in a way not permitted in these Terms, you may write to us to ask permission at legal@alpinemath.org.

DMCA compliance#

In fairness to our users, as well as to other creators and copyright holders, our policy is to respond to notices of alleged infringement that comply with the formalities of the Digital Millennium Copyright Act (DMCA). Pursuant to the DMCA, we will terminate, in appropriate circumstances, users and account holders of our Service who are repeat infringers.

However, we also recognize that not every takedown notice is valid or in good faith. In such cases, we strongly encourage users to file counter-notifications when they appropriately believe a DMCA takedown demand is invalid or improper. For more information on what to do if you think a DMCA notice has been improperly filed, you may wish to consult the Chilling Effects website.

If you are the owner of content that is being improperly used on our Site without your permission, you may request that the content be removed under the DMCA. To make such a request, please email us at legal@alpinemath.org, and include the following information in your request:

  • Your physical or electronic signature.

  • Identification of the copyrighted work you believe to have been infringed or, if the claim involves multiple works, a representative list of those works.

  • Identification of the material you believe to be infringing in a sufficiently precise manner to allow us to locate that material.

  • Adequate information by which we can contact the copyright owner or their agent (including their name, postal address, telephone number, and, if available, email address).

  • A statement that you have a good faith belief that use of the copyrighted material is not authorized by the copyright owner, its agent, or the law.

  • A statement that the information in the written notice is accurate.

  • A statement, under penalty of perjury, that you are authorized to act on behalf of the copyright owner.

However, we ask you to remember that, while we index and link to content, any content hosted at our site has already been published elsewhere, in the form of a code repository at a site like GitHub. Therefore, as an alternative to emailing us, you may make a request to our community by opening an issue in the offending project’s issue tracker.

Because any content hosted at our Site comes from a code repository, we believe opening an issue is the best and most focused way to make your request. Through the facilities of issue trackers at sites like GitHub, you can let the community members know exactly which parts of their code you believe to be infringing.

Management of websites#

We reserve the right, but do not have the obligation to:

  • Investigate your use of the Service (a) to determine whether a violation of these Terms of Service, or other applicable law or policy has occurred, or (b) to comply with any applicable law, legal process, or appropriate governmental request;

  • Detect, prevent, or otherwise address fraud, security, or technical issues or respond to user support requests;

  • Refuse, disable, or restrict access to, and indexing of, the contributions of any user who violates these Terms of Service;

  • Ban a user from contributing or block a user’s account or access for actions violating these Terms of Service, including repeat copyright infringement;

  • Take legal action against users who violate these Terms of Service (including reports to law enforcement authorities); and

  • Manage the Site in a manner designed to facilitate its proper functioning and protect the rights, property, and safety of ourselves and our users, licensors, partners, and the public.


While we hope you will continue to use the Site, and to offer your own projects for indexing, you can stop using our Service any time. Since we receive any content we index under the terms of the Mozilla Public License, version 2.0, we reserve the right to continue distributing such content as long as we comply with the terms of that license. In certain (hopefully unlikely) circumstances it may be necessary for us to terminate part or all of our services, terminate these Terms of Service, block your account or access, or ban you as a user. If your account or access is blocked or otherwise terminated for any reason, you may still access our public pages for the sole purpose of reading publicly available content. In such circumstances, however, you may not be able to access your account or settings. We reserve the right to suspend or end the Service at any time, with or without cause, and with or without notice. Even after your use and participation are banned, blocked or otherwise suspended, these Terms of Service will remain in effect with respect to relevant provisions.

Disputes and jurisdiction#




Limitation on liability#


Modifications to these Terms of Service#

Because it may be necessary to modify these Terms of Service from time to time, we will provide notice of such modifications via the Site. However, we ask that you please periodically review the most up-to-date version of these Terms of Service. Your continued use of our services after the new Terms of Service become official following the notice constitutes an acceptance of these Terms of Service on your part. For the protection of Alpine Mathematics and other users like yourself, if you do not agree with our Terms of Service, you cannot use our services.

Other terms#

These Terms of Service do not create an employment, agency, partnership, or joint venture relationship between you and us, Alpine Mathematics. If you have not signed a separate agreement with us, these Terms of Service are the entire agreement between you and us. If there is any conflict between these Terms of Service and a signed written agreement between you and us, the signed agreement will control.

You agree that we may provide you with notices, including those regarding changes to the Terms of Service, by email, or postings on the Site.

If in any circumstance, we do not apply or enforce any provision of these Terms of Service, it is not a waiver of that provision.

You understand that, unless otherwise agreed to in writing by us, you have no expectation of compensation for any activity, contribution, or idea that you provide to us or the community.

If any provision or part of a provision of these Terms of Service is found unlawful, void, or unenforceable, that provision or part of the provision is deemed severable from these Terms of Service and will be enforced to the maximum extent permissible, and all other provisions of these Terms of Service will remain in full force and effect.


If you need to get in touch with us about these Terms of Service, you can reach us at legal@alpinemath.org.

License and attribution for these Terms#

The text in some sections above is derived, with important modifications, from corresponding sections of the Terms of Use of the Wikimedia Foundation, and the Trademark Policy of the Wikimedia Foundation. We received the text of these documents under the CC BY-SA 3.0 license, and accordingly offer the text of these Terms under the same license. Alpine Mathematics is not affiliated in any way with the Wikimedia Foundation. While we have borrowed language from their documents, their terms are unrelated to ours, and only our Terms apply to you when you use our Services.