Semi-Formal Code Reasoning

SkillFiles & storage

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.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the Semi-Formal Code Reasoning skill

What this skill tells your AI

The instructions your AI receives, as published by oaustegard/claude-skills in reasoning-semiformally/SKILL.md and read by ahel’s review.

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 or similar): Read haiku.md in this skill directory. It contains full procedural templates with worked examples.

If you are Sonnet-class or above (Sonnet 5, Opus): 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.

Signals

GitHub stars
148
Forks
5
Last commit
Sep 2026
Advanced
Catalog kind
skill
Gateway key
reasoning-semiformally
Source
github.com/oaustegard/claude-skills