reasoning-semiformally SKILL.md skillA
This file is byte-identical to the first copy the registry indexed. Same content hash, so the same checks give both the same grade.
reasoning-semiformally from oaustegard/claude-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add oaustegard/claude-skills/reasoning-semiformally@v0.4.0Pins v0.4.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- oaustegard/claude-skills
- Path
reasoning-semiformally/SKILL.md- Versions recorded
- 6
- Latest version
- v0.4.0, committed Oct 7, 2026
- First version recorded
- Apr 2, 2026
- Size
- 1,586 bytes
- Repository stars
- 158
- License
- MIT
Apply semi-formal certificate reasoning to code analysis — patch verification, fault localization, patch equivalence. Use when reviewing patches, hunting bugs across scopes, comparing fixes, or when code reasoning requires tracing execution across files/modules. Triggers on code review, bug localization, patch comparison, name shadowing, scope analysis, regression checking.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Semi-Formal Code Reasoning Structured certificate templates that force mandatory checkpoints before conclusions. ## Skip Conditions Do NOT apply semi-formal reasoning when: - The change is trivial: docs, formatting, version bumps, config changes - The bug is locally obvious: typo, off-by-one in the same function, missing comma - No execution paths cross scope boundaries - The task is not code analysis (text editing, data extraction, summarization) If any skip condition is met, proceed with standard reasoning. ## Model-Specific Instructions **If you are Haiku-class (Haiku 4.5, Haiku 5.5):** Read `haiku.md` in this skill directory. It contains full procedural templates with worked examples. **If you are Sonnet-class or above (Sonnet 5, Sonnet 5.5, Opus, Fable):** Read `sonnet.md` in this skill directory. It contains compact verification checkpoints. ## Composing Tasks For complex tasks, apply templates sequentially: 1. **Fault localization** to find the bug 2. **Patch verification** to validate a proposed fix 3. **Patch equivalence** to compare alternative fixes Each output feeds the next as premises.
Read the whole file at its exact version.
How to install
mdr add oaustegard/claude-skills/reasoning-semiformally@sha256:fc7e89211c93798aThe line at the top of this page pins the label v0.4.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_z3ibicyhveyovbh7)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 6 versions of this file, between Apr 2, 2026 and Oct 7, 2026, about one every 38 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.4.0 latest | 2026-10-07 | 66d1719 | 1,586 B | A | view · diff |
| v0.3.1 | 2026-09-09 | db4e3e1 | 1,567 B | A | view · diff |
| v0.3.0 | 2026-07-25 | 4b31e7d | 1,569 B | A | view · diff |
| v0.3.0 | 2026-04-02 | a550dc8 | 1,557 B | A | view · diff |
| git:20260402.25614a4 | 2026-04-02 | 25614a4 | 2,083 B | A | view · diff |
| git:20260402.5ee41f6 | 2026-04-02 | 5ee41f6 | 6,760 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (1586 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
oaustegard/claude-skills · 158 stars · license MIT · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_z3ibicyhveyovbh7 GET https://markdownregistry.com/api/v1/resolve?ref=oaustegard/claude-skills/reasoning-semiformally GET https://markdownregistry.com/api/v1/blob/fc7e89211c93798a1689113d6b9fa792ce985bcd603e10fd5eecc17356180011
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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