reserve k,n for Element of NAT,
  a,Y for set,
  D,D1,D2 for non empty set,
  p,q for FinSequence of NAT;
reserve F,F1,G,G1,H,H1,H2 for CTL-formula;
reserve sq,sq9 for FinSequence;
reserve V for CTLModel;
reserve Kai for Function of atomic_WFF,the BasicAssign of V;
reserve f,f1,f2 for Function of CTL_WFF,the carrier of V;
reserve S for non empty set;
reserve R for total Relation of S,S;
reserve s,s0,s1 for Element of S;
reserve BASSIGN for non empty Subset of ModelSP(S);
reserve kai for Function of atomic_WFF,the BasicAssign of BASSModel(R,BASSIGN);

theorem
  s,kai|= EX H iff ex pai being inf_path of R st pai.0 = s & (pai.1),kai |= H
proof
A1: (ex pai being inf_path of R st pai.0 = s & (pai.1) |= Evaluate(H,kai) )
  implies ex pai being inf_path of R st pai.0 = s & (pai.1),kai|= H
  by Def60;
  s,kai|= EX H iff s|= EX Evaluate(H,kai) by Th7;
  hence thesis by A1,Th14;
end;
