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Live demo

These pages are the web reader of three example articles, built from the reports their certificates wrote. Each is a short paper in the usual style, with an introduction and references, and each renders from its LaTeX source with a marker at the start of every sentence. Select a marker to see what Lean checked for that sentence: its formal reading, its Lean statement, its definedness condition, the premises it rests on and the declaration that justifies it.

  • The certified note


    A number and its reciprocal, the note of the tutorial: a short article with an introduction, remarks between the results and references. Every one of its 7 claims is derived in the text from what it cites, and the explanations around them are prose.

    Open the reader

  • The draft with a false theorem


    The same note at step 6 of the tutorial: the theorem says f(x) > 2, Lean refutes it at x = 1, and the corollary that rests on it is not verified.

    Open the reader

  • Three means


    The harmonic, geometric and arithmetic mean of two numbers: symbols defined inside a theorem, in a where-clause and in apposition, and an equality case read as "if and only if". 16 claims, all verified.

    Open the reader

The reader of the draft: Theorem 3.1 is selected, its reading is shown with the three premises it rests on and the refutation

The markers

Marker Status of the sentence
Derived from its citations: a proof step, or a result whose proof compiled, proved in Lean from exactly what it rests on
Checked by a companion development: a result stated without a compiled proof, proved in Lean
A definition, well defined
Compiled, not yet verified: no proof yet, or it rests on a claim that is not verified
False as stated: refuted in Lean
Not compiled: an undefined symbol or a construction the grammar does not read
Prose: it asserts nothing checked

The summary at the top of each page counts the claims by status, and the legend filters the markers.

The files behind the pages

Page Folder Files
The certified note examples/Demo article · proofs · report · draft
The draft with a false theorem tests/Refuted article · proofs · report
Three means examples/Means article · proofs · report

CI certifies all three on every push, so the reports cannot go stale. To build the reader of your own article, see step 8 of the tutorial.