Section ATOMIC.
Variable L: semantics.
Hypothesis Lwb: well_behaved_traces L.
Remark atomic_finish: forall s t, output_trace t -> Star (atomic L) (t, s) t (E0, s).

Lemma step_atomic_plus:
forall s1 t s2, Step L s1 t s2 -> Plus (atomic L) (E0,s1) t (E0,s2).