theorem
  for p1 being FinSequence, p2 being FinSubsequence st i >= len p1
  holds p1 misses Shift(p2,i)
proof
  let p1 be FinSequence, p2 be FinSubsequence;
  assume i >= len p1;
  then dom p1 misses dom Shift(p2,i) by Th47;
  hence thesis by RELAT_1:179   ;
end;
