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Proof of `Every regular function is computed by a two-way transducer`

groundedproofs/Lax916827Proofs/Results.lean · lax-916827

What this proof establishes

no assumptions

Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.

Read the Lean proof on GitHub

In the paper

Description

Every regular function is computed by a two-way transducer (Corollary C.2.8): induction on the composition tree with Theorem C.2.5 and Corollary C.2.7, and explicit two-way transducers for map reverse and map duplicate (Transducers.regularFunisTwoWayTransducers.regularFun_isTwoWay).

Attribution

Corollary C.2.8 of Transducers, Part C; formalised by Aristotle (Harmonic), PartC/Statements.leanPartC/Statements.lean, PartC/TwoWaySweep.leanPartC/TwoWaySweep.lean.