Find the Index of the First Occurrence in a String

Invariant: Before processing the next text character, j is the maximum prefix length equal to a suffix of the processed text.

candidate confidence: 0.520 · metadata_only

Invariant: The first True always lies in [lo,hi]; indexes left of lo are proven False, while hi remains a feasible candidate.

candidate confidence: 0.488 · metadata_only

Invariant: Every uneliminated pair uses endpoints inside [l,r]; a moved endpoint is proven unable to pair with any remaining opposite endpoint to satisfy the goal.

candidate confidence: 0.452 · metadata_only

Invariant: After processing a[0:read], a[0:write] is exactly its correct stable filtered output, with write no farther than read+1.

candidate confidence: 0.434 · metadata_only