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 Th25:
  for s0 holds ex pai being inf_path of R st pai.0 = s0
proof
  let s0;
  consider pai being sequence of S such that
A1: pai.0=s0 and
A2: for n being Nat holds [pai.n,pai.(n+1)] in R by Lm33;
  reconsider pai as inf_path of R by A2,Def39;
  take pai;
  thus thesis by A1;
end;
