The S7 merge kept both branches' doc comments for the Books structure, S5's (which names the sends) stranded above an unrelated theorem and S7's on the structure; Lean refused the stray one. S5's text stays, on the structure it describes. Kani's 52 harnesses verified in the same run; only Lean's build stopped. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp