AI tutor (optional)

The checker works fully without any key (✓/×, the reasons, Unstuck). A key adds an AI tutor that knows everything on your board: a plain-English explanation under every step, the Ask box, Explain next step, and AI study notes in the PDF. It uses NVIDIA’s free API under your own account.

1. Open build.nvidia.com and sign in (Google login is fine).
2. Open any model page (e.g. nemotron) → Get API Key → Generate Key.
3. Copy the key (it starts with nvapi-) and paste it here.

Explain every step automatically — after each line you check, the AI tutor writes 1–2 sentences under it using your actual formulas (for ✗ lines: what went wrong)

Stored only in this browser. Sent to this site’s relay for each question and passed straight to NVIDIA — never saved on the server, never logged.

Export as PDF

A clean study sheet of this derivation: the statements, every step with its rule and the law written out, and the checker’s notes. Your browser’s print window opens — choose Save as PDF.

Include my wrong attempts (with what was wrong) Add AI study notes — a strategy summary, and a “why” for every step (the step explanations you saw on screen) Include my Ask questions and answers