For writing or reviewing content for Lemma — applies the manifesto bar, the arc structure (hook → widget → numbered arc → pin → exercises → glossary), the Term backlink rule, and two-doors discipline. Use when planning a new module or application, drafting prose, or reviewing a draft for ship-readiness.
For translating between Korean and English in Lemma, QA-ing existing translations, or triaging which prose needs rework. Use when adding the counterpart locale to new content, when reviewing for awkward calque, or when the user flags translation quality.
For cold-reading a Lemma page as a zero-context reader and surfacing defects across four axes — fact, fluency, interest, awkwardness. Use when the user says "read this", "give feedback on this page", "is this boring?", "fact-check this", "QA before I ship", or otherwise hands you finished-looking content and asks how it lands. Different lens from `content` (author), `translate` (bilingual), and `professor` (real-user) — this is the simulated cold-reader lens.
For helping the user learn a concept by working through an existing or freshly-drafted Lemma page, treating their real confusion as page-level defect reports, and refining the page so the next reader gains. Use when the user says "teach me X", "I want to learn X", "I'm stuck on Y in the [page]", or "update this page based on what I just asked". The output is always a better page, not a chat answer. Lemma is _not_ a curriculum (per the manifesto) — the page teaches, the user reads, this skill closes the loop.