Rules

Accounts

Submitting

Submit plain text, Markdown with LaTeX, or files: photos, scans, PDFs, .md.
Write the full argument, not just the answer.
You can submit as many times as you like.
Uploads must be legible.

Marking

Each problem is marked out of 10 by a reviewer, who gives one of four verdicts.

Pending, not looked at yet.
Accepted, correct and complete.
Partial, partly right.
Rejected, wrong or unreadable.

Contest scoring

Each contest question has a multiplier chosen by the contest setter. Your leaderboard points for that question are your best mark times its multiplier. For example, a score of 8 on a 3× question is 24 points. Labels such as 1×A, 2×B and 3×C show the weights directly.

Ratings

Ratings change only for contests marked as rated, after the contest ends and every submission is graded. For each question, an Elo curve compares your current rating with the question difficulty to predict an expected mark. Both your best mark and that expected mark are multiplied by the question multiplier.

The difference between total weighted actual and expected marks is divided by 10, multiplied by a K-factor, and rounded. The K-factor is 48 for your first three rated contests, 32 for the next five, and 24 afterwards. Ratings cannot fall below zero. An admin applies the changes once, and can revert the exact changes if grading needs correction.

Conduct

Do not submit work that is not yours, and do not share solutions while a contest is running.