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  <!-- Pipeline éditorial des papers -->
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  <!-- Catalogue Lean des théorèmes (avec D3 dependency graph) -->
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  <!-- Λ_{S,k} explorer interactif -->
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  <!-- Research Ledger — public versioned registry (Three-Key validated 2026-04-30) -->
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  <!-- Syracuse / Collatz reference page (FR market SEO entry point) -->
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  <!-- FAQ — bilingual Q&A with FAQPage schema -->
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  <!-- Histoire / History — timeline 1937-2026 -->
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