Lean 4 formalization of Erdős Problem #848 – seeking review

Formalized the Sawhney-Sellke stability theorem for Erdős Problem #848 (squarefree products) in Lean 4.

~3800 lines, compiles with 0 errors, no sorries, no axioms.

The math was solved by Sawhney & Sellke (Nov 2025): https://arxiv.org/abs/2511.16072

Only ~17 Erdős problems have full solutions formalized in Lean. If valid, this would be ~#18.

Done with multiple AI tools (Claude Opus 4.5, GPT-5.2, Gemini 3.0, Aristotle) + human orchestration.

Seeking review: Does this actually prove what it claims? The code is verbose and could be cleaner. Would appreciate expert eyes.