[ScottishTapWater]

Summary

• Add a core English rational parser using typed tokens and left-to-right integer parsing.
• Support signed integers, named fractions through millionths, and XOverY spellings, with grammar validation and BigInteger arithmetic.
• Use the parser as a fallback in Rational.TryParse, preserving numeric parsing and number styles. Rational.Parse remains unchanged.
• Add focused parser tests and Rational parsing regressions; generator discovery is outside this change.

Verification

• Independent C# production and test reviews completed; the missing agreed grammar regression was added and re-reviewed.
• Solution build: zero warnings and errors.
• Full suite: 645 tests passed, including the packaged-consumer integration test.
• Formatting verification and git diff --check passed.

[ScottishTapWater]

@codex review

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	🔄 Running since 2026-10-24T09:28:04.106603Z	4e94c68	Manual request

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