Logic-Lens — Semantic Diff

Setup

Use lazy loading per ../_shared/common.md §13:

1. Read ../_shared/common.md only for language, Iron Law, Verdict header, scope routing, Remedy discipline, config fields, and loading budget.
2. Read only the relevant step in logic-diff-guide.md as you reach it.
3. Load ../_shared/logic-risks.md, ../_shared/semiformal-guide.md, ../_shared/semiformal-checklist.md, and ../_shared/report-template.md on demand when the current step needs them.

Process

Step 0. Language + scope routing. Detect language per common.md §1. Confirm two versions are provided. If only one version, switch to logic-review.

Step 1. Identify the shared specification (guide Step 1) — what inputs should both versions handle; what outputs/side effects are expected. If the user states the refactor intentionally changed behavior in a specific area (e.g., "I changed the error path to raise instead of returning None"), record that as a declared spec change and treat divergences within that area as expected. Flag only divergences outside the declared change as findings.

Step 2. Build independent premises for each version (guide Step 2) — apply the Premises Construction Checklist to Version A and Version B separately.

Step 3. Trace both versions for the common case (guide Step 3) — parallel trace, same input, note the first divergence if any.