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Proof of `Balanced runs between configurations are regular`

groundedproofs/Lax194892Proofs/Results.lean · lax-194892

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.

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In the paper

Description

For every height 1,,kℓ ∈ {1, …, k}, the string representations of pairs of configurations of height connected by a balanced run form a regular language (Claim D.2.3), Transducers.reachabilitybasicrunTransducers.reachability_basic_run.

Proof strategy

The same pebble automaton as for Lemma D.2.2, restricted to runs that never pop below height (Transducers.PebEnc.reachLangMTransducers.PebEnc.reachLang M ℓ); the concept's balanced run is the source's restricted reachability, transported by balancedRuntoSrcPebbalancedRun_toSrcPeb.

Attribution

Claim D.2.3 of Transducers, Part D; formalised by Aristotle (Harmonic), PartD/PebReach.leanPartD/PebReach.lean.