language-posture-design.md

1. Scope

This document defines the Bilingual Invariant — the rule that governs which content in VeriPower is English-only and which is bilingual. It is read by skill authors when writing or translating skills, references, design docs, or framework code.

Audience. Skill authors; framework maintainers; reviewers.

Companion documents.

• skill-structure-design.md — skill and reference organization; a separate concern from language posture.

2. Background

VeriPower serves both Chinese and English users — as designers using the tool and as contributors writing skills. The Invariant draws the boundary: content the LLM consumes at runtime is English; content that flows between the agent and the user follows the user's language.

3. Surface 1 — runtime-LLM-consumed content (English)

Content that the skill dispatcher, the executing agent, or the eval harness loads into the agent's context window at runtime is Surface 1 and is strict English.

Exemplars: skills/<name>/SKILL.md (frontmatter + body); skills/<name>/references/*.md (when linked from SKILL.md).

Note — matcher pattern data. A Surface-1 script may carry Surface-2 literal tokens as matcher pattern data when its job is to detect user-language content. Such tokens are matched data, not authored Surface-1 prose; the script's own agent-facing output stays English.

4. Surface 2 — user-data interfaces (bilingual)

Content that is free-prose, flows between the agent and the user, or is read/written by the agent as a data value inside an artifact or message body is Surface 2 and follows user language. It is not parsed as fields by any matcher.

Exemplar: live agent↔user dialogue; runtime artifact prose in brainstorm.md body cells and design.md cell content.

5. The two-stage test

For any content, determine its tier with two questions:

Stage 1 — runtime vs. offline:

"Does any dispatcher, harness, or executing agent load this file into the agent's context window during a skill or eval run?"

• Yes → continue to Stage 2.
• No → project documentation; language follows the audience; not a Surface (see §7).

Stage 2 — parsed vs. content (only for runtime-loaded files):

"Is this content parsed as a data field, referenced by name, validated by schema, or used as an input to a matcher?"

• Yes → Surface 1 (English).
• No → Surface 2 (user language; free-prose content in a structural slot).

6. Anchor example

Surface 1 example:

## When to Use

- Write or revise the design.md spec.
- Not for: RTL implementation, verification, or synthesis.

At runtime, dialogue follows the language the user has been writing in.

7. Not a Surface — project documentation

Project documentation is read by humans offline. Its language follows its audience; the runtime language convention applies to skill instructions and artifacts.

Committed bilingual mirrors. A few human-facing docs carry a committed .zh.md mirror for Chinese readers (such as ARCHITECTURE.zh.md and USER-MANUAL.zh.md). A mirror is a translation of its English source, not an independent document: the English source is authoritative and the mirror MUST be updated in the same change as that source, to keep their facts aligned.