Draft — mutable and not usable as a dependency; its citation marks the draft state.

Proof of `Two-way transducers are closed under pre-composition with rational functions`

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

Two-way transducers are closed under pre-composition with rational functions (Corollary C.2.7), through the prime decomposition of Theorem B.2.6 (Transducers.twoWayprecomprationalTransducers.twoWay_precomp_rational); Part B's bridge transports IsRationalFunIsRationalFun.

Attribution

Corollary C.2.7 of Transducers, Part C; formalised by Aristotle (Harmonic), PartC/TwoWayRat.leanPartC/TwoWayRat.lean, PartC/TwoWayHom.leanPartC/TwoWayHom.lean.