Rigor Mortis turns proof-checking into a forensic lab

Field notes

The case navigator filters the collection by IMO year, topic, theorem, or title, and separates near-miss examples from valid controls. Its own limitations are unusually explicit: a “clean” fragment is valid only under its stated hypotheses, and some cases address an intermediate lemma rather than a whole Olympiad solution. The page also says classroom label-hiding is only a UI convenience because author keys are shipped to the browser.