theorem
  ex p st p is FinSequence of E & rng p = e & len p = 1
proof
  consider a such that
  a in E and
A1: e = {a} by Th6;
  rng <*a*> = {a} & len <*a*> = 1 by FINSEQ_1:39;
  hence thesis by A1;
end;
