Language equivalence for Aho's bounded simulation #
This module isolates the final grammar/machine language argument. Soundness is unconditional; the completeness hypothesis is precisely the uniform twenty-one-slots-per-terminal theorem supplied by the parse-directed scheduler.
theorem
IndexedGrammar.Aho.language_eq_paddedReachLanguage_of_bounded_complete
{T : Type}
{g : IndexedGrammar T}
[Fintype g.nt]
[DecidableEq g.nt]
(hNF : g.IsNormalForm)
(hcomplete :
∀ {input : List T} (a : g.NFParse g.initial [] input),
BoundedReaches g input (21 * input.length) (initialConfig g) (finalConfig g input.length))
:
Once every concrete normal-form parse has a twenty-one-linear bounded run, semantic padded-row reachability recognizes exactly the language of the grammar.