
theorem Th24:
  for P,Q being Element of absolute holds
  ex R being Element of real_projective_plane st
  R in tangent P & R in tangent Q
  proof
    let P,Q being Element of absolute;
    reconsider pP = tangent P,pQ = tangent Q as
    LINE of IncProjSp_of real_projective_plane by INCPROJ:4;
    consider R being POINT of IncProjSp_of real_projective_plane such that
A1: R on pP and
A2: R on pQ by BKMODEL1:75,INCPROJ:def 9;
    reconsider S = R as Element of real_projective_plane by INCPROJ:3;
    S in tangent P & S in tangent Q by A1,A2,INCPROJ:5;
    hence thesis;
  end;
