Certificate soundness for Aho's machine #
Every certified composite step has its stated grammar or input-consumption effect.
Every finite certificate is denotationally sound #
theorem
IndexedGrammar.Aho.ControlDenotation.certStep_preserves_represents
{T : Type}
{g : IndexedGrammar T}
[Fintype g.nt]
(input : List T)
(cert : CompositeCert g)
{c c' : Config g}
{form : List g.ISym}
(hstep : CertStep g input cert c c')
(hrep : Config.Represents c form)
:
∃ (form' : List g.ISym), Config.Represents c' form' ∧ StepEffect g input c c' form form'