logic-diff
Compare two code versions for semantic equivalence via semi-formal tracing of both versions side-by-side. Trigger when the user shares a refactor, rewrite, migration, or A/B implementation and wants to confirm behavior is unchanged — "did I break anything", "is this equivalent", "are...
Profile →npx skills add sickn33/agentic-awesome-skills --skill logic-diff --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Logic-Lens — Semantic Diff ## When to Use Use this skill when you need compare two code versions for semantic equivalence via semi-formal tracing of both versions side-by-side. Trigger when the user shares a refactor, rewrite, migration, or A/B implementation and wants to confirm behavior is unchanged — "did I break anything", "is this equivalent", "are... ## 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
- When to Use
- Setup
- Process
- Limitations
What does the logic-diff skill do?
Compare two code versions for semantic equivalence via semi-formal tracing of both versions side-by-side. Trigger when the user shares a refactor, rewrite, migration, or A/B implementation and wants to confirm behavior is unchanged — "did I break anything", "is this equivalent", "are...
How do I install it?
Run `npx skills add sickn33/agentic-awesome-skills --skill logic-diff --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From sickn33/agentic-awesome-skills, a repository with 44,414 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.