theorem :: ANPROJ11:31

for P being non zero_proj1 non zero_proj2 Point of (ProjectiveSpace (TOP-REAL 3))
for u being non zero Element of (TOP-REAL 3) st P = Dir u holds
( normalize_proj1 P = |[1,((u . 2) / (u . 1)),((u . 3) / (u . 1))]| & normalize_proj2 P = |[((u . 1) / (u . 2)),1,((u . 3) / (u . 2))]| ) by Th11, Th14;