# Proof Grammar Export Boundary

> A proof grammar fixture in which a safe export sits between an allowlisted command and an exit report. The export owns that status while remaining setup for later proofs. Never distributed. Trigger phrases - "export report boundary", "safe export continuation test".

- Skill: `island-dev-crew/proof-grammar-export-boundary` (Agent Skill)
- Install (CLI): `npx skillmds@latest add island-dev-crew/proof-grammar-export-boundary`
- Raw SKILL.md: https://api.skillmd.com/api/skills/island-dev-crew/proof-grammar-export-boundary/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Docs & Writing
- Author: Island-Dev-Crew (https://skillmd.com/u/island-dev-crew)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/island-dev-crew/proof-grammar-export-boundary

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# Export report boundary

`export` is status-producing shell syntax. The first report belongs to it, not to Python. The
second block proves an accepted export still replays as setup when a later proof is inline.

- `enforced`: strict mode returns 4 for the pending first Python candidate; the continuation control runs and matches 0.
- `advisory`: nothing else here is real.

```bash
python3 -c "import sys; sys.exit(0)"
export LANG=C
echo $? # -> 0
```

```bash
export LANG=C
python3 -c "import os,sys; sys.exit(0 if os.environ.get('LANG') == 'C' else 1)"   # exit 0
```