# Operational Semantics Builder

> Define and test operational semantics specifications for programming languages

- Skill: `a5c-ai/operational-semantics-builder` (Agent Skill)
- Install (CLI): `npx skillmds@latest add a5c-ai/operational-semantics-builder`
- Raw SKILL.md: https://api.skillmd.com/api/skills/a5c-ai/operational-semantics-builder/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: a5c-ai (https://skillmd.com/u/a5c-ai)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/a5c-ai/operational-semantics-builder

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# Operational Semantics Builder

## Purpose

Provides expert guidance on defining operational semantics for programming language specification and testing.

## Capabilities

- Small-step semantics rule generation
- Big-step semantics rule generation
- Evaluation context definition
- Substitution and binding handling
- Semantics execution/testing
- Equivalence proofs

## Usage Guidelines

1. **Semantics Style**: Choose small-step or big-step
2. **Rule Definition**: Define reduction/evaluation rules
3. **Contexts**: Define evaluation contexts if needed
4. **Testing**: Execute semantics on test programs
5. **Validation**: Verify expected behavior

## Tools/Libraries

- PLT Redex
- K Framework
- Ott
- Maude