Comment by lanstin

As for collaboration I meant: https://terrytao.wordpress.com/2024/09/25/a-pilot-project-in... The issue with horizontal scaling of maths research is trust: if you don't know the author, it is more work to verify their work, especially non-formal proofs. Lean4 enables large projects be split up into pieces where lean can validate each intermediate result, so a much broader group of people can contribute pieces without jeopardizing the overall soundness.