Section FineGrainedExecutions.
Context
{Sem : Semantics}
{initU : seq.seq nat}
{SemAx : CoreLanguage.SemAxioms}.
Existing Instance dryResources.
Existing Instance HybridFineMachine.scheduler.
Existing Instance OrdinalPool.OrdinalThreadPool.
Existing Instance DryHybridMachineSig.
Existing Instance FineDilMem.
Existing Instance dryFineMach.

Lemma step_ev_contains:
forall U tr tp m U' ev
tr_pre tr_post tp' m'
(Hstep: MachStep (U, tr, tp) m
(U', tr ++ tr_pre ++ [:: ev] ++ tr_post, tp') m'),
containsThread tp (thread_id ev) /\ containsThread tp' (thread_id ev).