Structured differencing and three-way merge

Document status: reviewed. Canonical source.

Summary

Structured merge research shows AST-aware mappings and top-down/bottom-up strategies can reduce false conflicts compared with line merge, particularly when elements move. Recent 2026 work also argues for explicit correctness properties for structural merge.

NUIF relevance

Stable entity identity gives NUIF an advantage over inferred AST matching. Three-way merge should operate over semantic operations and graph relationships while preserving a textual fallback for human review.