
theorem
  for h being Element of EnsK-isometry
  for N being invertible Matrix of 3,F_Real st
  h = homography(N) holds homography(N).:absolute = absolute
  proof
    let h being Element of EnsK-isometry;
    let N being invertible Matrix of 3,F_Real;
    assume
A1: h = homography(N);
    h in {h where h is Element of EnsHomography3: h is_K-isometry};
    then consider g be Element of EnsHomography3 such that
A2: h = g and
A3: g is_K-isometry;
    thus thesis by A1,A2,A3;
  end;
