reserve V for RealLinearSpace;

theorem Th14:
  for v being VECTOR of V, W1,W2 being Subspace of V ex v1,v2
  being VECTOR of V st v |-- (W1,W2) = [v1,v2]
proof
  let v be VECTOR of V, W1,W2 be Subspace of V;
  take (v |-- (W1,W2))`1,(v |-- (W1,W2))`2;
  thus thesis by MCART_1:21;
end;
