
theorem Th6:
  for f being FinSequence, k2 being Nat st len f<=k2 holds
    smid(f,1,k2)=f
proof
  let f be FinSequence,k2 be Nat;
  assume
A1: len f<=k2;
  thus smid(f,1,k2)=f|k2 by Th5
    .=f by A1,FINSEQ_1:58;
end;
