refactor(Encoding): hoist the pair projections out of the Cobham internals - #30
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BoltonBailey merged 1 commit intoAug 29, 2026
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…rnals `Cobham.fstBlock` / `Cobham.sndBlock` are the total decoders of the pairing codec, but they were defined in the Cobham proof internals, so any file wanting to decode a pair had to import those internals. Move them to `Complexitylib.Encoding.Pairing` next to `pair` / `unpair?` as `pairFst` / `pairSnd`, with `pairFst_pair` / `pairSnd_pair` and `pairSnd_eq_unpair?`, and rename every use. The scanner machines and their lemmas (`fstBlockTM`, `fstBlock_mem_FP`, …) keep their names. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
SamuelSchlesinger
approved these changes
Aug 28, 2026
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Summary
Cobham.fstBlock/Cobham.sndBlock— the total decoders of the pairing codec — lived in the Cobham proof internals, so anything wanting to decode a pair had to import those internals. This moves them toComplexitylib.Encoding.Pairing, next topair/unpair?, aspairFst/pairSnd, with the simp lemmaspairFst_pair/pairSnd_pairandpairSnd_eq_unpair?, and renames every use (~270 sites, all inside the Cobham internals). Scanner machines and their lemmas (fstBlockTM,fstBlock_mem_FP, …) keep their names.Pure relocation + rename; no new theorems beyond
pairSnd_eq_unpair?. #18 will be stacked on this.Verification
lake build --wfailplus both Validation executablespython3 scripts/lint_style.pycleanlake exe runLinterclean on every touched modulelake env lean scripts/AxiomGuard.lean: 42,974 declarations on standard axioms only🤖 Generated with Claude Code