
theorem
  for V being RealUnitarySpace, w1,w2 being VECTOR of V holds w1 in Lin{
  w1,w2} & w2 in Lin{w1,w2}
proof
  let V be RealUnitarySpace;
  let w1,w2 be VECTOR of V;
  w1 in {w1,w2} & w2 in {w1,w2} by TARSKI:def 2;
  hence thesis by Th2;
end;
