Terms of Service

Who can use Lemma

• You must be 13 or older to create an account.
• If you are under 18 (or under the age of adulthood where you live), please read these terms with a parent or guardian, who agrees to them for you.
• One account per person. Keep access to your email and sign-in secure, and tell us if you think someone else is using your account.

Your notes and your lessons

• You keep any rights you have in the notes you upload. You give us permission to store and process them (including sending them to our AI provider) only to make your lessons and run the service.
• Only upload material you are allowed to use, such as your own class notes and handouts from your own classes.
• Your lessons and the course pages are for your personal study. Don't share your account, resell, or republish them.

Acceptable use

Please don't:

• Use the site to cheat. Lessons are for learning; follow your school's rules about outside help on graded work and exams.
• Upload anything illegal, hateful, sexual, violent, or that invades someone else's privacy.
• Try to break, overload, or get around the site's security, limits, or credit system.
• Use bots or scripts to access the site, or copy it at scale.

We may suspend or close accounts that break these rules.

Accuracy

Lessons are made by an AI model following careful teaching instructions, and accuracy is our top priority. Even so, a lesson can contain mistakes. Lessons and courses are a study aid, not a replacement for your teacher, your textbook or your own judgment, and we can't promise any grade or exam score. Double-check anything that looks wrong, and please use the "Report a mistake" button so we can fix it.

Credits, payments and refunds

• New accounts get free credits, once per email address. Credits have no cash value and can't be transferred or sold.
• If a lesson can't be made because your notes aren't math, can't be read, or something goes wrong on our side, the credits for it are returned to your account automatically.
• Purchases are sold through Link, the checkout service of Stripe, which acts as the merchant of record for your payment. Link takes the payment, adds sales tax or VAT where it applies (shown at checkout before you pay), sends your receipt, and handles payment support. Link's own terms, shown at checkout, apply to the payment; these terms apply to your use of Lemma. Charges appear on your statement as LINK.COM* LEMMA. We never see or store your card number. Prices are in US dollars (checkout may show them in your local currency).
• Plans (weekly, monthly or yearly) renew automatically at the end of each period, and your payment method is charged each time, until you cancel. You can cancel any time from your Account page ("Manage plan") or in your Link account at link.com; you keep your plan until the end of the period you paid for, and it doesn't renew after that. A plan's credits reset at the start of each credit period (every week for the weekly plan, every month for the monthly and yearly plans) and unused plan credits don't carry over.
• Top-up packs are one-time purchases. Their credits never expire and are used after your plan's credits.
• The AP Calculus courses (AB for $39, and BC for $49, which includes AB) are one-time purchases, not subscriptions. A course stays open on your account for as long as we offer it.
• Someone else, such as a parent, can pay for your account with an "Ask a parent to pay" link. If you're under 18, ask a parent or guardian before buying anything.
• We may change prices. A new price for a plan applies from your next billing period after we tell you, and you can cancel before then.
• Refunds: payments are non-refundable, except where the law requires a refund (for example, the 14-day right to cancel that UK and EU consumers may have) or when we charged you by mistake. The Refund Policy explains how to ask. Link may also refund a payment within 60 days in some cases, and applies the cooling-off periods local law requires. If a payment is refunded or reversed, the course access or the unused credits it bought are removed.

Ending your account

You can delete your account at any time from the Account page ("Delete my account and data"). This cancels any plan so it doesn't renew, and permanently deletes your notes, lessons, progress, credits and access to any course you bought; these aren't refunded, except where the law requires. We may suspend or close an account that breaks these terms.

Disclaimers and limits

Lemma is provided "as is" and "as available". We work hard to keep it running and accurate, but we can't promise it will always be available or error-free. To the extent the law allows, we are not liable for indirect or consequential losses (such as a lost grade or exam result), and our total liability to you is limited to the amount you paid us in the 12 months before the claim. Nothing in these terms limits liability that cannot be limited by law, or your rights as a consumer that can't be waived.

Governing law

These terms are governed by the laws of the Commonwealth of Virginia, USA, without regard to its conflict-of-law rules. Any dispute will be heard in the state or federal courts located in Virginia, unless the law where you live gives you the right to bring a claim in your local courts.

Trademarks

AP is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this site.

Changes to these terms

If we make important changes, we'll update this page and the date at the top, and tell you on the site or by email. Using the site after a change means you accept the new terms.

Contact

Questions about these terms? Email support@lemmalessons.com, or write to Thomas Zheleznyak, 711 Utterback Store Road, Great Falls, VA 22066, USA.