theorem
  H is atomic implies (s,kai |= H iff kai.H in (Label_(BASSIGN)).s)
proof
  assume
A1: H is atomic;
  ex f be Function of CTL_WFF,the carrier of BASSModel(R, BASSIGN) st
  f is-Evaluation-for kai & Evaluate(H,kai) = f.H by Def34;
  then
A2: Evaluate(H,kai) = kai.H by A1;
  H in atomic_WFF by A1;
  then Evaluate(H,kai) in BASSIGN by A2,FUNCT_2:5;
  hence thesis by A2,Th11;
end;
