theorem
  StepTimes(a,I,p,s).0.f = s.f
proof
  set ST = StepTimes(a,I,p,s);
  set au = 1-stRWNotIn ({a} \/ UsedILoc I);
  set Is = Initialized s;
  thus ST.0.f = Exec(au := a, Is).f by SCMFSA_9:def 5
    .= Is.f by SCMFSA_2:63
    .= s.f by SCMFSA_M:37;
end;
