
theorem Th62:
  for P being Element of absolute holds
  P is non point_at_infty Element of ProjectiveSpace TOP-REAL 3
  proof
    let P be Element of absolute;
    consider u be non zero Element of TOP-REAL 3 such that
A1: u.3 = 1 and
A2: P = Dir u by BKMODEL3:30;
    u`3 = 1 by A1,EUCLID_5:def 3;
    hence thesis by A2,Th40;
  end;
