incproj.miz
    
    begin
    
    reserve CPS for
    proper  
    CollSp, 
    
B for
    Subset of CPS, 
    
p for
    Point of CPS, 
    
x,y,z,Y for
    set;
    
    definition
    
      let CPS;
    
      :: original:
    LINE
    
      redefine
    
      mode
    
    LINE of CPS -> 
    Subset of CPS ; 
    
      coherence
    
      proof
    
        let x be
    LINE of CPS; 
    
        x
    c= the 
    carrier of CPS 
    
        proof
    
          consider a,b be
    Point of CPS such that a 
    <> b and 
    
          
    
    A1: x 
    = ( 
    Line (a,b)) by 
    COLLSP:def 7;
    
          let z be
    object;
    
          assume z
    in x; 
    
          then z
    in { p : (a,b,p) 
    are_collinear } by 
    A1,
    COLLSP:def 5;
    
          then ex p be
    Point of CPS st z 
    = p & (a,b,p) 
    are_collinear ; 
    
          hence z
    in the 
    carrier of CPS; 
    
        end;
    
        hence thesis;
    
      end;
    
    end
    
    definition
    
      let CPS;
    
      :: 
    
    INCPROJ:def1
    
      func
    
    ProjectiveLines (CPS) -> 
    set equals { B : B is 
    LINE of CPS }; 
    
      coherence ;
    
    end
    
    registration
    
      let CPS;
    
      cluster ( 
    ProjectiveLines CPS) -> non 
    empty;
    
      coherence
    
      proof
    
        set x = the
    LINE of CPS; 
    
        x
    in ( 
    ProjectiveLines CPS); 
    
        hence thesis;
    
      end;
    
    end
    
    theorem :: 
    
    INCPROJ:1
    
    
    
    
    
    Th1: x is 
    LINE of CPS iff x is 
    Element of ( 
    ProjectiveLines CPS) 
    
    proof
    
      hereby
    
        assume x is
    LINE of CPS; 
    
        then x
    in { B : B is 
    LINE of CPS }; 
    
        hence x is
    Element of ( 
    ProjectiveLines CPS); 
    
      end;
    
      assume x is
    Element of ( 
    ProjectiveLines CPS); 
    
      then x
    in ( 
    ProjectiveLines CPS); 
    
      then ex B st x
    = B & B is 
    LINE of CPS; 
    
      hence thesis;
    
    end;
    
    definition
    
      let CPS;
    
      :: 
    
    INCPROJ:def2
    
      func
    
    Proj_Inc (CPS) -> 
    Relation of the 
    carrier of CPS, ( 
    ProjectiveLines CPS) means 
    
      :
    
    Def2: for x,y be 
    object holds 
    [x, y]
    in it iff x 
    in the 
    carrier of CPS & y 
    in ( 
    ProjectiveLines CPS) & ex Y st y 
    = Y & x 
    in Y; 
    
      existence
    
      proof
    
        defpred
    
    P[
    object, 
    object] means ex Y st $2
    = Y & $1 
    in Y; 
    
        ex IT be
    Relation of the 
    carrier of CPS, ( 
    ProjectiveLines CPS) st for x,y be 
    object holds 
    [x, y]
    in IT iff x 
    in the 
    carrier of CPS & y 
    in ( 
    ProjectiveLines CPS) & 
    P[x, y] from
    RELSET_1:sch 1;
    
        hence thesis;
    
      end;
    
      uniqueness
    
      proof
    
        let R1,R2 be
    Relation of the 
    carrier of CPS, ( 
    ProjectiveLines CPS) such that 
    
        
    
    A1: for x,y be 
    object holds 
    [x, y]
    in R1 iff x 
    in the 
    carrier of CPS & y 
    in ( 
    ProjectiveLines CPS) & ex Y st y 
    = Y & x 
    in Y and 
    
        
    
    A2: for x,y be 
    object holds 
    [x, y]
    in R2 iff x 
    in the 
    carrier of CPS & y 
    in ( 
    ProjectiveLines CPS) & ex Y st y 
    = Y & x 
    in Y; 
    
        now
    
          let x,y be
    object;
    
          
    
    A3: 
    
          now
    
            assume
    
            
    
    A4: 
    [x, y]
    in R2; 
    
            then
    
            
    
    A5: ex Y st y 
    = Y & x 
    in Y by 
    A2;
    
            x
    in the 
    carrier of CPS & y 
    in ( 
    ProjectiveLines CPS) by 
    A2,
    A4;
    
            hence
    [x, y]
    in R1 by 
    A1,
    A5;
    
          end;
    
          now
    
            assume
    
            
    
    A6: 
    [x, y]
    in R1; 
    
            then
    
            
    
    A7: ex Y st y 
    = Y & x 
    in Y by 
    A1;
    
            x
    in the 
    carrier of CPS & y 
    in ( 
    ProjectiveLines CPS) by 
    A1,
    A6;
    
            hence
    [x, y]
    in R2 by 
    A2,
    A7;
    
          end;
    
          hence
    [x, y]
    in R1 iff 
    [x, y]
    in R2 by 
    A3;
    
        end;
    
        hence R1
    = R2 by 
    RELAT_1:def 2;
    
      end;
    
    end
    
    definition
    
      let CPS;
    
      :: 
    
    INCPROJ:def3
    
      func
    
    IncProjSp_of (CPS) -> 
    IncProjStr equals 
    IncProjStr (# the 
    carrier of CPS, ( 
    ProjectiveLines CPS), ( 
    Proj_Inc CPS) #); 
    
      coherence ;
    
    end
    
    registration
    
      let CPS;
    
      cluster ( 
    IncProjSp_of CPS) -> 
    strict;
    
      coherence ;
    
    end
    
    theorem :: 
    
    INCPROJ:2
    
    the
    Points of ( 
    IncProjSp_of CPS) 
    = the 
    carrier of CPS & the 
    Lines of ( 
    IncProjSp_of CPS) 
    = ( 
    ProjectiveLines CPS) & the 
    Inc of ( 
    IncProjSp_of CPS) 
    = ( 
    Proj_Inc CPS); 
    
    theorem :: 
    
    INCPROJ:3
    
    x is
    Point of CPS iff x is 
    POINT of ( 
    IncProjSp_of CPS); 
    
    theorem :: 
    
    INCPROJ:4
    
    x is
    LINE of CPS iff x is 
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
    reserve a,b,c,p,q for
    POINT of ( 
    IncProjSp_of CPS), 
    
P,Q for
    LINE of ( 
    IncProjSp_of CPS), 
    
a9,b9,c9,p9,q9,r9 for
    Point of CPS, 
    
P9 for
    LINE of CPS; 
    
    theorem :: 
    
    INCPROJ:5
    
    
    
    
    
    Th5: p 
    = p9 & P 
    = P9 implies (p 
    on P iff p9 
    in P9) 
    
    proof
    
      reconsider P99 = P9 as
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
      reconsider P999 = P99 as
    Element of ( 
    ProjectiveLines CPS); 
    
      assume
    
      
    
    A1: p 
    = p9 & P 
    = P9; 
    
      hereby
    
        assume p
    on P; 
    
        then
    [p9, P9]
    in ( 
    Proj_Inc CPS) by 
    A1;
    
        then ex Y st P9
    = Y & p9 
    in Y by 
    Def2;
    
        hence p9
    in P9; 
    
      end;
    
      assume p9
    in P9; 
    
      then
    [p9, P999]
    in ( 
    Proj_Inc CPS) by 
    Def2;
    
      hence thesis by
    A1;
    
    end;
    
    theorem :: 
    
    INCPROJ:6
    
    
    
    
    
    Th6: ex a9, b9, c9 st a9 
    <> b9 & b9 
    <> c9 & c9 
    <> a9 
    
    proof
    
      consider a99,b99,c99 be
    Point of CPS such that 
    
      
    
    A1: not (a99,b99,c99) 
    are_collinear by 
    COLLSP:def 6;
    
      
    
      
    
    A2: c99 
    <> a99 by 
    A1,
    COLLSP: 2;
    
      a99
    <> b99 & b99 
    <> c99 by 
    A1,
    COLLSP: 2;
    
      hence thesis by
    A2;
    
    end;
    
    theorem :: 
    
    INCPROJ:7
    
    
    
    
    
    Th7: ex b9 st a9 
    <> b9 
    
    proof
    
      consider p9, q9, r9 such that
    
      
    
    A1: p9 
    <> q9 and q9 
    <> r9 and r9 
    <> p9 by 
    Th6;
    
      a9
    <> p9 or a9 
    <> q9 by 
    A1;
    
      hence thesis;
    
    end;
    
    theorem :: 
    
    INCPROJ:8
    
    
    
    
    
    Th8: p 
    on P & q 
    on P & p 
    on Q & q 
    on Q implies p 
    = q or P 
    = Q 
    
    proof
    
      reconsider p9 = p, q9 = q as
    Point of CPS; 
    
      reconsider P9 = P, Q9 = Q as
    LINE of CPS by 
    Th1;
    
      assume that
    
      
    
    A1: p 
    on P & q 
    on P and 
    
      
    
    A2: p 
    on Q & q 
    on Q and 
    
      
    
    A3: p 
    <> q; 
    
      
    
      
    
    A4: p9 
    in Q9 & q9 
    in Q9 by 
    A2,
    Th5;
    
      p9
    in P9 & q9 
    in P9 by 
    A1,
    Th5;
    
      hence thesis by
    A3,
    A4,
    COLLSP: 20;
    
    end;
    
    theorem :: 
    
    INCPROJ:9
    
    
    
    
    
    Th9: ex P st p 
    on P & q 
    on P 
    
    proof
    
      reconsider p9 = p, q9 = q as
    Point of CPS; 
    
      
    
    A1: 
    
      now
    
        consider r9 such that
    
        
    
    A2: p9 
    <> r9 by 
    Th7;
    
        consider P9 be
    LINE of CPS such that 
    
        
    
    A3: p9 
    in P9 and r9 
    in P9 by 
    A2,
    COLLSP: 15;
    
        reconsider P = P9 as
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
        assume
    
        
    
    A4: p9 
    = q9; 
    
        p
    on P by 
    A3,
    Th5;
    
        hence thesis by
    A4;
    
      end;
    
      now
    
        assume p9
    <> q9; 
    
        then
    
        consider P9 be
    LINE of CPS such that 
    
        
    
    A5: p9 
    in P9 & q9 
    in P9 by 
    COLLSP: 15;
    
        reconsider P = P9 as
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
        p
    on P & q 
    on P by 
    A5,
    Th5;
    
        hence thesis;
    
      end;
    
      hence thesis by
    A1;
    
    end;
    
    theorem :: 
    
    INCPROJ:10
    
    
    
    
    
    Th10: a 
    = a9 & b 
    = b9 & c 
    = c9 implies ((a9,b9,c9) 
    are_collinear iff ex P st a 
    on P & b 
    on P & c 
    on P) 
    
    proof
    
      assume that
    
      
    
    A1: a 
    = a9 and 
    
      
    
    A2: b 
    = b9 and 
    
      
    
    A3: c 
    = c9; 
    
      hereby
    
        assume
    
        
    
    A4: (a9,b9,c9) 
    are_collinear ; 
    
        
    
    A5: 
    
        now
    
          set X = (
    Line (a9,b9)); 
    
          assume a9
    <> b9; 
    
          then
    
          reconsider P9 = X as
    LINE of CPS by 
    COLLSP:def 7;
    
          reconsider P = P9 as
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
          a9
    in X by 
    COLLSP: 10;
    
          then
    
          
    
    A6: a 
    on P by 
    A1,
    Th5;
    
          b9
    in X by 
    COLLSP: 10;
    
          then
    
          
    
    A7: b 
    on P by 
    A2,
    Th5;
    
          c9
    in X by 
    A4,
    COLLSP: 11;
    
          then c
    on P by 
    A3,
    Th5;
    
          hence ex P st a
    on P & b 
    on P & c 
    on P by 
    A6,
    A7;
    
        end;
    
        now
    
          assume
    
          
    
    A8: a9 
    = b9; 
    
          ex P st b
    on P & c 
    on P by 
    Th9;
    
          hence ex P st a
    on P & b 
    on P & c 
    on P by 
    A1,
    A2,
    A8;
    
        end;
    
        hence ex P st a
    on P & b 
    on P & c 
    on P by 
    A5;
    
      end;
    
      given P such that
    
      
    
    A9: a 
    on P & b 
    on P and 
    
      
    
    A10: c 
    on P; 
    
      reconsider P9 = P as
    LINE of CPS by 
    Th1;
    
      
    
      
    
    A11: c9 
    in P9 by 
    A3,
    A10,
    Th5;
    
      a9
    in P9 & b9 
    in P9 by 
    A1,
    A2,
    A9,
    Th5;
    
      hence thesis by
    A11,
    COLLSP: 16;
    
    end;
    
    theorem :: 
    
    INCPROJ:11
    
    
    
    
    
    Th11: ex p, P st not p 
    on P 
    
    proof
    
      consider p9, q9, r9 such that
    
      
    
    A1: not (p9,q9,r9) 
    are_collinear by 
    COLLSP:def 6;
    
      set X = (
    Line (p9,q9)); 
    
      p9
    <> q9 by 
    A1,
    COLLSP: 2;
    
      then
    
      reconsider P9 = X as
    LINE of CPS by 
    COLLSP:def 7;
    
      reconsider P = P9 as
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
      reconsider r = r9 as
    POINT of ( 
    IncProjSp_of CPS); 
    
       not r
    on P 
    
      proof
    
        assume not thesis;
    
        then r9
    in X by 
    Th5;
    
        hence contradiction by
    A1,
    COLLSP: 11;
    
      end;
    
      hence thesis;
    
    end;
    
    reserve CPS for
    CollProjectiveSpace, 
    
a,b,c,d,p,q for
    POINT of ( 
    IncProjSp_of CPS), 
    
P,Q,S,M,N for
    LINE of ( 
    IncProjSp_of CPS), 
    
a9,b9,c9,d9,p9,q9 for
    Point of CPS; 
    
    theorem :: 
    
    INCPROJ:12
    
    
    
    
    
    Th12: ex a, b, c st a 
    <> b & b 
    <> c & c 
    <> a & a 
    on P & b 
    on P & c 
    on P 
    
    proof
    
      reconsider P9 = P as
    LINE of CPS by 
    Th1;
    
      consider a99,b99 be
    Point of CPS such that 
    
      
    
    A1: a99 
    <> b99 and 
    
      
    
    A2: P9 
    = ( 
    Line (a99,b99)) by 
    COLLSP:def 7;
    
      consider c9 such that
    
      
    
    A3: a99 
    <> c9 & b99 
    <> c9 and 
    
      
    
    A4: (a99,b99,c9) 
    are_collinear by 
    ANPROJ_2:def 10;
    
      reconsider a = a99, b = b99, c = c9 as
    POINT of ( 
    IncProjSp_of CPS); 
    
      take a, b, c;
    
      thus a
    <> b & b 
    <> c & c 
    <> a by 
    A1,
    A3;
    
      a99
    in P9 by 
    A2,
    COLLSP: 10;
    
      then
    
      
    
    A5: a 
    on P by 
    Th5;
    
      b99
    in P9 by 
    A2,
    COLLSP: 10;
    
      then
    
      
    
    A6: b 
    on P by 
    Th5;
    
      ex Q st a
    on Q & b 
    on Q & c 
    on Q by 
    A4,
    Th10;
    
      hence thesis by
    A1,
    A5,
    A6,
    Th8;
    
    end;
    
    theorem :: 
    
    INCPROJ:13
    
    
    
    
    
    Th13: a 
    on M & b 
    on M & c 
    on N & d 
    on N & p 
    on M & p 
    on N & a 
    on P & c 
    on P & b 
    on Q & d 
    on Q & not p 
    on P & not p 
    on Q & M 
    <> N implies ex q st q 
    on P & q 
    on Q 
    
    proof
    
      assume that
    
      
    
    A1: a 
    on M and 
    
      
    
    A2: b 
    on M and 
    
      
    
    A3: c 
    on N and 
    
      
    
    A4: d 
    on N and 
    
      
    
    A5: p 
    on M & p 
    on N and 
    
      
    
    A6: a 
    on P and 
    
      
    
    A7: c 
    on P and 
    
      
    
    A8: b 
    on Q and 
    
      
    
    A9: d 
    on Q and 
    
      
    
    A10: not p 
    on P and 
    
      
    
    A11: not p 
    on Q and 
    
      
    
    A12: M 
    <> N; 
    
      reconsider a9 = a, b9 = b, c9 = c, d9 = d, p9 = p as
    Point of CPS; 
    
      (b9,p9,a9)
    are_collinear & (p9,d9,c9) 
    are_collinear by 
    A1,
    A2,
    A3,
    A4,
    A5,
    Th10;
    
      then
    
      consider q9 such that
    
      
    
    A13: (b9,d9,q9) 
    are_collinear and 
    
      
    
    A14: (a9,c9,q9) 
    are_collinear by 
    ANPROJ_2:def 9;
    
      reconsider q = q9 as
    POINT of ( 
    IncProjSp_of CPS); 
    
      
    
      
    
    A15: ex P2 be 
    LINE of ( 
    IncProjSp_of CPS) st b 
    on P2 & d 
    on P2 & q 
    on P2 by 
    A13,
    Th10;
    
      b
    <> d by 
    A2,
    A4,
    A5,
    A8,
    A11,
    A12,
    Th8;
    
      then
    
      
    
    A16: q 
    on Q by 
    A8,
    A9,
    A15,
    Th8;
    
      
    
      
    
    A17: ex P1 be 
    LINE of ( 
    IncProjSp_of CPS) st a 
    on P1 & c 
    on P1 & q 
    on P1 by 
    A14,
    Th10;
    
      a
    <> c by 
    A1,
    A3,
    A5,
    A6,
    A10,
    A12,
    Th8;
    
      then q
    on P by 
    A6,
    A7,
    A17,
    Th8;
    
      hence thesis by
    A16;
    
    end;
    
    theorem :: 
    
    INCPROJ:14
    
    
    
    
    
    Th14: (for a9, b9, c9, d9 holds ex p9 st (a9,b9,p9) 
    are_collinear & (c9,d9,p9) 
    are_collinear ) implies for M, N holds ex q st q 
    on M & q 
    on N 
    
    proof
    
      assume
    
      
    
    A1: for a9, b9, c9, d9 holds ex p9 st (a9,b9,p9) 
    are_collinear & (c9,d9,p9) 
    are_collinear ; 
    
      let M, N;
    
      reconsider M9 = M, N9 = N as
    LINE of CPS by 
    Th1;
    
      consider a9, b9 such that a9
    <> b9 and 
    
      
    
    A2: M9 
    = ( 
    Line (a9,b9)) by 
    COLLSP:def 7;
    
      consider c9, d9 such that c9
    <> d9 and 
    
      
    
    A3: N9 
    = ( 
    Line (c9,d9)) by 
    COLLSP:def 7;
    
      consider p9 such that
    
      
    
    A4: (a9,b9,p9) 
    are_collinear and 
    
      
    
    A5: (c9,d9,p9) 
    are_collinear by 
    A1;
    
      reconsider q = p9 as
    POINT of ( 
    IncProjSp_of CPS); 
    
      p9
    in N9 by 
    A3,
    A5,
    COLLSP: 11;
    
      then
    
      
    
    A6: q 
    on N by 
    Th5;
    
      p9
    in M9 by 
    A2,
    A4,
    COLLSP: 11;
    
      then q
    on M by 
    Th5;
    
      hence thesis by
    A6;
    
    end;
    
    theorem :: 
    
    INCPROJ:15
    
    
    
    
    
    Th15: (ex p,p1,r,r1 be 
    Point of CPS st not ex s be 
    Point of CPS st ((p,p1,s) 
    are_collinear & (r,r1,s) 
    are_collinear )) implies ex M, N st not ex q st q 
    on M & q 
    on N 
    
    proof
    
      given p,p1,r,r1 be
    Point of CPS such that 
    
      
    
    A1: not ex s be 
    Point of CPS st ((p,p1,s) 
    are_collinear & (r,r1,s) 
    are_collinear ); 
    
      set M99 = (
    Line (p,p1)), N99 = ( 
    Line (r,r1)); 
    
      p
    <> p1 & r 
    <> r1 
    
      proof
    
        
    
    A2: 
    
        now
    
          assume p
    = p1; 
    
          then
    
          
    
    A3: (p,p1,r1) 
    are_collinear by 
    COLLSP: 2;
    
          (r,r1,r1)
    are_collinear by 
    COLLSP: 2;
    
          hence contradiction by
    A1,
    A3;
    
        end;
    
        
    
    A4: 
    
        now
    
          assume r
    = r1; 
    
          then (p,p1,p1)
    are_collinear & (r,r1,p1) 
    are_collinear by 
    COLLSP: 2;
    
          hence contradiction by
    A1;
    
        end;
    
        assume not thesis;
    
        hence contradiction by
    A2,
    A4;
    
      end;
    
      then
    
      reconsider M9 = M99, N9 = N99 as
    LINE of CPS by 
    COLLSP:def 7;
    
      reconsider M = M9, N = N9 as
    LINE of ( 
    IncProjSp_of CPS) by 
    Th1;
    
      take M, N;
    
      thus not ex q st q
    on M & q 
    on N 
    
      proof
    
        assume not thesis;
    
        then
    
        consider q such that
    
        
    
    A5: q 
    on M and 
    
        
    
    A6: q 
    on N; 
    
        reconsider q9 = q as
    Point of CPS; 
    
        q9
    in N99 by 
    A6,
    Th5;
    
        then
    
        
    
    A7: (r,r1,q9) 
    are_collinear by 
    COLLSP: 11;
    
        q9
    in M99 by 
    A5,
    Th5;
    
        then (p,p1,q9)
    are_collinear by 
    COLLSP: 11;
    
        hence contradiction by
    A1,
    A7;
    
      end;
    
    end;
    
    theorem :: 
    
    INCPROJ:16
    
    
    
    
    
    Th16: (for p,p1,q,q1,r2 be 
    Point of CPS holds ex r,r1 be 
    Point of CPS st (p,q,r) 
    are_collinear & (p1,q1,r1) 
    are_collinear & (r2,r,r1) 
    are_collinear ) implies for a, M, N holds ex b, c, S st a 
    on S & b 
    on S & c 
    on S & b 
    on M & c 
    on N 
    
    proof
    
      assume
    
      
    
    A1: for p,p1,q,q1,r2 be 
    Point of CPS holds ex r,r1 be 
    Point of CPS st (p,q,r) 
    are_collinear & (p1,q1,r1) 
    are_collinear & (r2,r,r1) 
    are_collinear ; 
    
      let a, M, N;
    
      reconsider M9 = M, N9 = N as
    LINE of CPS by 
    Th1;
    
      reconsider a9 = a as
    Point of CPS; 
    
      consider p,q be
    Point of CPS such that p 
    <> q and 
    
      
    
    A2: M9 
    = ( 
    Line (p,q)) by 
    COLLSP:def 7;
    
      consider p1,q1 be
    Point of CPS such that p1 
    <> q1 and 
    
      
    
    A3: N9 
    = ( 
    Line (p1,q1)) by 
    COLLSP:def 7;
    
      consider b9, c9 such that
    
      
    
    A4: (p,q,b9) 
    are_collinear and 
    
      
    
    A5: (p1,q1,c9) 
    are_collinear and 
    
      
    
    A6: (a9,b9,c9) 
    are_collinear by 
    A1;
    
      reconsider b = b9, c = c9 as
    POINT of ( 
    IncProjSp_of CPS); 
    
      b9
    in M9 by 
    A2,
    A4,
    COLLSP: 11;
    
      then
    
      
    
    A7: b 
    on M by 
    Th5;
    
      c9
    in N9 by 
    A3,
    A5,
    COLLSP: 11;
    
      then
    
      
    
    A8: c 
    on N by 
    Th5;
    
      ex S st a
    on S & b 
    on S & c 
    on S by 
    A6,
    Th10;
    
      hence thesis by
    A7,
    A8;
    
    end;
    
    theorem :: 
    
    INCPROJ:17
    
    
    
    
    
    Th17: (for p1,r2,q,r1,q1,p,r be 
    Point of CPS holds ((p1,r2,q) 
    are_collinear & (r1,q1,q) 
    are_collinear & (p1,r1,p) 
    are_collinear & (r2,q1,p) 
    are_collinear & (p1,q1,r) 
    are_collinear & (r2,r1,r) 
    are_collinear & (p,q,r) 
    are_collinear implies ((p1,r2,q1) 
    are_collinear or (p1,r2,r1) 
    are_collinear or (p1,r1,q1) 
    are_collinear or (r2,r1,q1) 
    are_collinear ))) implies for p,q,r,s,a,b,c be 
    POINT of ( 
    IncProjSp_of CPS) holds for L,Q,R,S,A,B,C be 
    LINE of ( 
    IncProjSp_of CPS) st not q 
    on L & not r 
    on L & not p 
    on Q & not s 
    on Q & not p 
    on R & not r 
    on R & 
    {a, p, s}
    on L & 
    {a, q, r}
    on Q & 
    {b, q, s}
    on R & 
    {b, p, r}
    on S & 
    {c, p, q}
    on A & 
    {c, r, s}
    on B & 
    {a, b}
    on C holds not c 
    on C 
    
    proof
    
      assume
    
      
    
    A1: for p1,r2,q,r1,q1,p,r be 
    Element of CPS holds ((p1,r2,q) 
    are_collinear & (r1,q1,q) 
    are_collinear & (p1,r1,p) 
    are_collinear & (r2,q1,p) 
    are_collinear & (p1,q1,r) 
    are_collinear & (r2,r1,r) 
    are_collinear & (p,q,r) 
    are_collinear implies ((p1,r2,q1) 
    are_collinear or (p1,r2,r1) 
    are_collinear or (p1,r1,q1) 
    are_collinear or (r2,r1,q1) 
    are_collinear )); 
    
      let p,q,r,s,a,b,c be
    POINT of ( 
    IncProjSp_of CPS); 
    
      let L,Q,R,S,A,B,C be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
      
    
    A2: not q 
    on L and 
    
      
    
    A3: not r 
    on L and 
    
      
    
    A4: not p 
    on Q and 
    
      
    
    A5: not s 
    on Q and 
    
      
    
    A6: not p 
    on R and 
    
      
    
    A7: not r 
    on R and 
    
      
    
    A8: 
    {a, p, s}
    on L and 
    
      
    
    A9: 
    {a, q, r}
    on Q and 
    
      
    
    A10: 
    {b, q, s}
    on R and 
    
      
    
    A11: 
    {b, p, r}
    on S and 
    
      
    
    A12: 
    {c, p, q}
    on A and 
    
      
    
    A13: 
    {c, r, s}
    on B and 
    
      
    
    A14: 
    {a, b}
    on C; 
    
      reconsider p9 = p, q9 = q, r9 = r, s9 = s, a9 = a, b9 = b, c9 = c as
    Point of CPS; 
    
      
    
      
    
    A15: p 
    on L & s 
    on L by 
    A8,
    INCSP_1: 2;
    
      
    
      
    
    A16: s 
    on R by 
    A10,
    INCSP_1: 2;
    
      
    
    A17: 
    
      now
    
        assume (p9,r9,s9)
    are_collinear ; 
    
        then
    
        
    
    A18: ex K be 
    LINE of ( 
    IncProjSp_of CPS) st p 
    on K & r 
    on K & s 
    on K by 
    Th10;
    
        hence s
    on S by 
    A3,
    A6,
    A15,
    A16,
    Th8;
    
        thus contradiction by
    A3,
    A6,
    A15,
    A16,
    A18,
    Th8;
    
      end;
    
      
    
    A19: 
    
      now
    
        assume (p9,s9,q9)
    are_collinear ; 
    
        then
    
        
    
    A20: ex K be 
    LINE of ( 
    IncProjSp_of CPS) st p 
    on K & s 
    on K & q 
    on K by 
    Th10;
    
        hence p
    on R by 
    A2,
    A15,
    A16,
    Th8;
    
        thus contradiction by
    A2,
    A6,
    A15,
    A16,
    A20,
    Th8;
    
      end;
    
      a
    on L by 
    A8,
    INCSP_1: 2;
    
      then
    
      
    
    A21: (p9,s9,a9) 
    are_collinear by 
    A15,
    Th10;
    
      assume
    
      
    
    A22: not thesis; 
    
      a
    on C & b 
    on C by 
    A14,
    INCSP_1: 1;
    
      then
    
      
    
    A23: (a9,b9,c9) 
    are_collinear by 
    A22,
    Th10;
    
      
    
      
    
    A24: q 
    on Q & r 
    on Q by 
    A9,
    INCSP_1: 2;
    
      
    
      
    
    A25: q 
    on R by 
    A10,
    INCSP_1: 2;
    
      
    
    A26: 
    
      now
    
        assume (p9,r9,q9)
    are_collinear ; 
    
        then
    
        
    
    A27: ex K be 
    LINE of ( 
    IncProjSp_of CPS) st p 
    on K & r 
    on K & q 
    on K by 
    Th10;
    
        hence q
    on S by 
    A4,
    A7,
    A24,
    A25,
    Th8;
    
        thus contradiction by
    A4,
    A7,
    A24,
    A25,
    A27,
    Th8;
    
      end;
    
      
    
    A28: 
    
      now
    
        assume (r9,s9,q9)
    are_collinear ; 
    
        then
    
        
    
    A29: ex K be 
    LINE of ( 
    IncProjSp_of CPS) st r 
    on K & s 
    on K & q 
    on K by 
    Th10;
    
        hence r
    on R by 
    A5,
    A24,
    A25,
    Th8;
    
        thus contradiction by
    A5,
    A7,
    A24,
    A25,
    A29,
    Th8;
    
      end;
    
      a
    on Q by 
    A9,
    INCSP_1: 2;
    
      then
    
      
    
    A30: (r9,q9,a9) 
    are_collinear by 
    A24,
    Th10;
    
      
    
      
    
    A31: r 
    on S by 
    A11,
    INCSP_1: 2;
    
      b
    on S & p 
    on S by 
    A11,
    INCSP_1: 2;
    
      then
    
      
    
    A32: (p9,r9,b9) 
    are_collinear by 
    A31,
    Th10;
    
      
    
      
    
    A33: s 
    on B by 
    A13,
    INCSP_1: 2;
    
      c
    on B & r 
    on B by 
    A13,
    INCSP_1: 2;
    
      then
    
      
    
    A34: (r9,s9,c9) 
    are_collinear by 
    A33,
    Th10;
    
      
    
      
    
    A35: q 
    on A by 
    A12,
    INCSP_1: 2;
    
      c
    on A & p 
    on A by 
    A12,
    INCSP_1: 2;
    
      then
    
      
    
    A36: (p9,q9,c9) 
    are_collinear by 
    A35,
    Th10;
    
      b
    on R by 
    A10,
    INCSP_1: 2;
    
      then (s9,q9,b9)
    are_collinear by 
    A25,
    A16,
    Th10;
    
      hence contradiction by
    A1,
    A23,
    A32,
    A21,
    A30,
    A36,
    A34,
    A26,
    A17,
    A19,
    A28;
    
    end;
    
    theorem :: 
    
    INCPROJ:18
    
    
    
    
    
    Th18: (for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be 
    Point of CPS st o 
    <> q1 & p1 
    <> q1 & o 
    <> q2 & p2 
    <> q2 & o 
    <> q3 & p3 
    <> q3 & not (o,p1,p2) 
    are_collinear & not (o,p1,p3) 
    are_collinear & not (o,p2,p3) 
    are_collinear & (p1,p2,r3) 
    are_collinear & (q1,q2,r3) 
    are_collinear & (p2,p3,r1) 
    are_collinear & (q2,q3,r1) 
    are_collinear & (p1,p3,r2) 
    are_collinear & (q1,q3,r2) 
    are_collinear & (o,p1,q1) 
    are_collinear & (o,p2,q2) 
    are_collinear & (o,p3,q3) 
    are_collinear holds (r1,r2,r3) 
    are_collinear ) implies for o,b1,a1,b2,a2,b3,a3,r,s,t be 
    POINT of ( 
    IncProjSp_of CPS) holds for C1,C2,C3,A1,A2,A3,B1,B2,B3 be 
    LINE of ( 
    IncProjSp_of CPS) st 
    {o, b1, a1}
    on C1 & 
    {o, a2, b2}
    on C2 & 
    {o, a3, b3}
    on C3 & 
    {a3, a2, t}
    on A1 & 
    {a3, r, a1}
    on A2 & 
    {a2, s, a1}
    on A3 & 
    {t, b2, b3}
    on B1 & 
    {b1, r, b3}
    on B2 & 
    {b1, s, b2}
    on B3 & (C1,C2,C3) 
    are_mutually_distinct & o 
    <> a1 & o 
    <> a2 & o 
    <> a3 & o 
    <> b1 & o 
    <> b2 & o 
    <> b3 & a1 
    <> b1 & a2 
    <> b2 & a3 
    <> b3 holds ex O be 
    LINE of ( 
    IncProjSp_of CPS) st 
    {r, s, t}
    on O 
    
    proof
    
      assume
    
      
    
    A1: for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be 
    Element of CPS st o 
    <> q1 & p1 
    <> q1 & o 
    <> q2 & p2 
    <> q2 & o 
    <> q3 & p3 
    <> q3 & not (o,p1,p2) 
    are_collinear & not (o,p1,p3) 
    are_collinear & not (o,p2,p3) 
    are_collinear & (p1,p2,r3) 
    are_collinear & (q1,q2,r3) 
    are_collinear & (p2,p3,r1) 
    are_collinear & (q2,q3,r1) 
    are_collinear & (p1,p3,r2) 
    are_collinear & (q1,q3,r2) 
    are_collinear & (o,p1,q1) 
    are_collinear & (o,p2,q2) 
    are_collinear & (o,p3,q3) 
    are_collinear holds (r1,r2,r3) 
    are_collinear ; 
    
      let o,b1,a1,b2,a2,b3,a3,r,s,t be
    POINT of ( 
    IncProjSp_of CPS); 
    
      let C1,C2,C3,A1,A2,A3,B1,B2,B3 be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
      
    
    A2: 
    {o, b1, a1}
    on C1 and 
    
      
    
    A3: 
    {o, a2, b2}
    on C2 and 
    
      
    
    A4: 
    {o, a3, b3}
    on C3 and 
    
      
    
    A5: 
    {a3, a2, t}
    on A1 and 
    
      
    
    A6: 
    {a3, r, a1}
    on A2 and 
    
      
    
    A7: 
    {a2, s, a1}
    on A3 and 
    
      
    
    A8: 
    {t, b2, b3}
    on B1 and 
    
      
    
    A9: 
    {b1, r, b3}
    on B2 and 
    
      
    
    A10: 
    {b1, s, b2}
    on B3 and 
    
      
    
    A11: (C1,C2,C3) 
    are_mutually_distinct and 
    
      
    
    A12: o 
    <> a1 & o 
    <> a2 & o 
    <> a3 and 
    
      
    
    A13: o 
    <> b1 and 
    
      
    
    A14: o 
    <> b2 and 
    
      
    
    A15: o 
    <> b3 and 
    
      
    
    A16: a1 
    <> b1 & a2 
    <> b2 & a3 
    <> b3; 
    
      reconsider o9 = o, b19 = b1, a19 = a1, b29 = b2, a29 = a2, b39 = b3, a39 = a3, r9 = r, s9 = s, t9 = t as
    Element of CPS; 
    
      
    
      
    
    A17: o 
    on C2 & b2 
    on C2 by 
    A3,
    INCSP_1: 2;
    
      
    
      
    
    A18: s 
    on B3 by 
    A10,
    INCSP_1: 2;
    
      b2
    on B3 & b1 
    on B3 by 
    A10,
    INCSP_1: 2;
    
      then
    
      
    
    A19: (b19,b29,s9) 
    are_collinear by 
    A18,
    Th10;
    
      
    
      
    
    A20: r 
    on B2 by 
    A9,
    INCSP_1: 2;
    
      b3
    on B2 & b1 
    on B2 by 
    A9,
    INCSP_1: 2;
    
      then
    
      
    
    A21: (b19,b39,r9) 
    are_collinear by 
    A20,
    Th10;
    
      
    
      
    
    A22: t 
    on B1 by 
    A8,
    INCSP_1: 2;
    
      b3
    on B1 & b2 
    on B1 by 
    A8,
    INCSP_1: 2;
    
      then
    
      
    
    A23: (b29,b39,t9) 
    are_collinear by 
    A22,
    Th10;
    
      
    
      
    
    A24: s 
    on A3 by 
    A7,
    INCSP_1: 2;
    
      a2
    on A3 & a1 
    on A3 by 
    A7,
    INCSP_1: 2;
    
      then
    
      
    
    A25: (a19,a29,s9) 
    are_collinear by 
    A24,
    Th10;
    
      
    
      
    
    A26: o 
    on C3 & b3 
    on C3 by 
    A4,
    INCSP_1: 2;
    
      a3
    on C3 by 
    A4,
    INCSP_1: 2;
    
      then
    
      
    
    A27: (o9,b39,a39) 
    are_collinear by 
    A26,
    Th10;
    
      a2
    on C2 by 
    A3,
    INCSP_1: 2;
    
      then
    
      
    
    A28: (o9,b29,a29) 
    are_collinear by 
    A17,
    Th10;
    
      
    
      
    
    A29: r 
    on A2 by 
    A6,
    INCSP_1: 2;
    
      a3
    on A2 & a1 
    on A2 by 
    A6,
    INCSP_1: 2;
    
      then
    
      
    
    A30: (a19,a39,r9) 
    are_collinear by 
    A29,
    Th10;
    
      
    
      
    
    A31: t 
    on A1 by 
    A5,
    INCSP_1: 2;
    
      a3
    on A1 & a2 
    on A1 by 
    A5,
    INCSP_1: 2;
    
      then
    
      
    
    A32: (a29,a39,t9) 
    are_collinear by 
    A31,
    Th10;
    
      
    
      
    
    A33: o 
    on C1 & b1 
    on C1 by 
    A2,
    INCSP_1: 2;
    
      
    
      
    
    A34: not (o9,b19,b29) 
    are_collinear & not (o9,b19,b39) 
    are_collinear & not (o9,b29,b39) 
    are_collinear  
    
      proof
    
        
    
    A35: 
    
        now
    
          assume (o9,b19,b39)
    are_collinear ; 
    
          then
    
          consider K be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
          
    
    A36: o 
    on K & b1 
    on K & b3 
    on K by 
    Th10;
    
          K
    = C1 & K 
    = C3 by 
    A13,
    A15,
    A33,
    A26,
    A36,
    Th8;
    
          hence contradiction by
    A11,
    ZFMISC_1:def 5;
    
        end;
    
        
    
    A37: 
    
        now
    
          assume (o9,b19,b29)
    are_collinear ; 
    
          then
    
          consider K be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
          
    
    A38: o 
    on K & b1 
    on K & b2 
    on K by 
    Th10;
    
          K
    = C1 & K 
    = C2 by 
    A13,
    A14,
    A33,
    A17,
    A38,
    Th8;
    
          hence contradiction by
    A11,
    ZFMISC_1:def 5;
    
        end;
    
        
    
    A39: 
    
        now
    
          assume (o9,b29,b39)
    are_collinear ; 
    
          then
    
          consider K be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
          
    
    A40: o 
    on K & b2 
    on K & b3 
    on K by 
    Th10;
    
          K
    = C2 & K 
    = C3 by 
    A14,
    A15,
    A17,
    A26,
    A40,
    Th8;
    
          hence contradiction by
    A11,
    ZFMISC_1:def 5;
    
        end;
    
        assume not thesis;
    
        hence contradiction by
    A37,
    A35,
    A39;
    
      end;
    
      a1
    on C1 by 
    A2,
    INCSP_1: 2;
    
      then (o9,b19,a19)
    are_collinear by 
    A33,
    Th10;
    
      then (t9,r9,s9)
    are_collinear by 
    A1,
    A12,
    A16,
    A19,
    A25,
    A21,
    A30,
    A23,
    A32,
    A28,
    A27,
    A34;
    
      then
    
      consider O be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
      
    
    A41: t 
    on O & r 
    on O & s 
    on O by 
    Th10;
    
      
    {r, s, t}
    on O by 
    A41,
    INCSP_1: 2;
    
      hence thesis;
    
    end;
    
    theorem :: 
    
    INCPROJ:19
    
    
    
    
    
    Th19: (for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be 
    Point of CPS st o 
    <> p2 & o 
    <> p3 & p2 
    <> p3 & p1 
    <> p2 & p1 
    <> p3 & o 
    <> q2 & o 
    <> q3 & q2 
    <> q3 & q1 
    <> q2 & q1 
    <> q3 & not (o,p1,q1) 
    are_collinear & (o,p1,p2) 
    are_collinear & (o,p1,p3) 
    are_collinear & (o,q1,q2) 
    are_collinear & (o,q1,q3) 
    are_collinear & (p1,q2,r3) 
    are_collinear & (q1,p2,r3) 
    are_collinear & (p1,q3,r2) 
    are_collinear & (p3,q1,r2) 
    are_collinear & (p2,q3,r1) 
    are_collinear & (p3,q2,r1) 
    are_collinear holds (r1,r2,r3) 
    are_collinear ) implies for o,a1,a2,a3,b1,b2,b3,c1,c2,c3 be 
    POINT of ( 
    IncProjSp_of CPS) holds for A1,A2,A3,B1,B2,B3,C1,C2,C3 be 
    LINE of ( 
    IncProjSp_of CPS) st (o,a1,a2,a3) 
    are_mutually_distinct & (o,b1,b2,b3) 
    are_mutually_distinct & A3 
    <> B3 & o 
    on A3 & o 
    on B3 & 
    {a2, b3, c1}
    on A1 & 
    {a3, b1, c2}
    on B1 & 
    {a1, b2, c3}
    on C1 & 
    {a1, b3, c2}
    on A2 & 
    {a3, b2, c1}
    on B2 & 
    {a2, b1, c3}
    on C2 & 
    {b1, b2, b3}
    on A3 & 
    {a1, a2, a3}
    on B3 & 
    {c1, c2}
    on C3 holds c3 
    on C3 
    
    proof
    
      assume
    
      
    
    A1: for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be 
    Point of CPS st o 
    <> p2 & o 
    <> p3 & p2 
    <> p3 & p1 
    <> p2 & p1 
    <> p3 & o 
    <> q2 & o 
    <> q3 & q2 
    <> q3 & q1 
    <> q2 & q1 
    <> q3 & not (o,p1,q1) 
    are_collinear & (o,p1,p2) 
    are_collinear & (o,p1,p3) 
    are_collinear & (o,q1,q2) 
    are_collinear & (o,q1,q3) 
    are_collinear & (p1,q2,r3) 
    are_collinear & (q1,p2,r3) 
    are_collinear & (p1,q3,r2) 
    are_collinear & (p3,q1,r2) 
    are_collinear & (p2,q3,r1) 
    are_collinear & (p3,q2,r1) 
    are_collinear holds (r1,r2,r3) 
    are_collinear ; 
    
      let o,a1,a2,a3,b1,b2,b3,c1,c2,c3 be
    POINT of ( 
    IncProjSp_of CPS); 
    
      let A1,A2,A3,B1,B2,B3,C1,C2,C3 be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
      
    
    A2: (o,a1,a2,a3) 
    are_mutually_distinct and 
    
      
    
    A3: (o,b1,b2,b3) 
    are_mutually_distinct and 
    
      
    
    A4: A3 
    <> B3 and 
    
      
    
    A5: o 
    on A3 and 
    
      
    
    A6: o 
    on B3 and 
    
      
    
    A7: 
    {a2, b3, c1}
    on A1 and 
    
      
    
    A8: 
    {a3, b1, c2}
    on B1 and 
    
      
    
    A9: 
    {a1, b2, c3}
    on C1 and 
    
      
    
    A10: 
    {a1, b3, c2}
    on A2 and 
    
      
    
    A11: 
    {a3, b2, c1}
    on B2 and 
    
      
    
    A12: 
    {a2, b1, c3}
    on C2 and 
    
      
    
    A13: 
    {b1, b2, b3}
    on A3 and 
    
      
    
    A14: 
    {a1, a2, a3}
    on B3 and 
    
      
    
    A15: 
    {c1, c2}
    on C3; 
    
      reconsider o9 = o, a19 = a1, a29 = a2, a39 = a3, b19 = b1, b29 = b2, b39 = b3, c19 = c1, c29 = c2, c39 = c3 as
    Point of CPS; 
    
      
    
      
    
    A16: b1 
    on A3 by 
    A13,
    INCSP_1: 2;
    
      
    
      
    
    A17: c3 
    on C1 by 
    A9,
    INCSP_1: 2;
    
      a1
    on C1 & b2 
    on C1 by 
    A9,
    INCSP_1: 2;
    
      then
    
      
    
    A18: (a19,b29,c39) 
    are_collinear by 
    A17,
    Th10;
    
      
    
      
    
    A19: c1 
    on A1 by 
    A7,
    INCSP_1: 2;
    
      
    
      
    
    A20: o9 
    <> b39 & b29 
    <> b39 by 
    A3,
    ZFMISC_1:def 6;
    
      
    
      
    
    A21: a29 
    <> a39 & a19 
    <> a29 by 
    A2,
    ZFMISC_1:def 6;
    
      
    
      
    
    A22: b3 
    on A2 & c2 
    on A2 by 
    A10,
    INCSP_1: 2;
    
      
    
      
    
    A23: a1 
    on A2 by 
    A10,
    INCSP_1: 2;
    
      then
    
      
    
    A24: (a19,b39,c29) 
    are_collinear by 
    A22,
    Th10;
    
      
    
      
    
    A25: b19 
    <> b29 & b19 
    <> b39 by 
    A3,
    ZFMISC_1:def 6;
    
      
    
      
    
    A26: b3 
    on A1 by 
    A7,
    INCSP_1: 2;
    
      
    
      
    
    A27: a1 
    on B3 by 
    A14,
    INCSP_1: 2;
    
      
    
      
    
    A28: not (o9,a19,b19) 
    are_collinear  
    
      proof
    
        
    
        
    
    A29: o 
    <> a1 by 
    A2,
    ZFMISC_1:def 6;
    
        assume not thesis;
    
        then
    
        consider K be
    LINE of ( 
    IncProjSp_of CPS) such that 
    
        
    
    A30: o 
    on K and 
    
        
    
    A31: a1 
    on K and 
    
        
    
    A32: b1 
    on K by 
    Th10;
    
        o
    <> b1 by 
    A3,
    ZFMISC_1:def 6;
    
        then K
    = A3 by 
    A5,
    A16,
    A30,
    A32,
    Th8;
    
        hence contradiction by
    A4,
    A6,
    A27,
    A30,
    A31,
    A29,
    Th8;
    
      end;
    
      
    
      
    
    A33: c3 
    on C2 by 
    A12,
    INCSP_1: 2;
    
      a2
    on C2 & b1 
    on C2 by 
    A12,
    INCSP_1: 2;
    
      then
    
      
    
    A34: (b19,a29,c39) 
    are_collinear by 
    A33,
    Th10;
    
      
    
      
    
    A35: a3 
    on B1 by 
    A8,
    INCSP_1: 2;
    
      
    
      
    
    A36: b2 
    on A3 by 
    A13,
    INCSP_1: 2;
    
      then
    
      
    
    A37: (o9,b19,b29) 
    are_collinear by 
    A5,
    A16,
    Th10;
    
      
    
      
    
    A38: a3 
    on B2 & c1 
    on B2 by 
    A11,
    INCSP_1: 2;
    
      
    
      
    
    A39: b2 
    on B2 by 
    A11,
    INCSP_1: 2;
    
      then
    
      
    
    A40: (a39,b29,c19) 
    are_collinear by 
    A38,
    Th10;
    
      
    
      
    
    A41: b3 
    on A3 by 
    A13,
    INCSP_1: 2;
    
      then
    
      
    
    A42: (o9,b19,b39) 
    are_collinear by 
    A5,
    A16,
    Th10;
    
      
    
      
    
    A43: a19 
    <> a39 & o9 
    <> b29 by 
    A2,
    A3,
    ZFMISC_1:def 6;
    
      
    
      
    
    A44: o9 
    <> a29 & o9 
    <> a39 by 
    A2,
    ZFMISC_1:def 6;
    
      
    
      
    
    A45: c2 
    on B1 by 
    A8,
    INCSP_1: 2;
    
      
    
      
    
    A46: a2 
    on A1 by 
    A7,
    INCSP_1: 2;
    
      then
    
      
    
    A47: (a29,b39,c19) 
    are_collinear by 
    A26,
    A19,
    Th10;
    
      
    
      
    
    A48: b1 
    <> b2 by 
    A3,
    ZFMISC_1:def 6;
    
      
    
      
    
    A49: a1 
    <> a2 by 
    A2,
    ZFMISC_1:def 6;
    
      
    
      
    
    A50: o 
    <> b3 by 
    A3,
    ZFMISC_1:def 6;
    
      
    
      
    
    A51: b1 
    on B1 by 
    A8,
    INCSP_1: 2;
    
      then
    
      
    
    A52: (a39,b19,c29) 
    are_collinear by 
    A35,
    A45,
    Th10;
    
      
    
      
    
    A53: a3 
    on B3 by 
    A14,
    INCSP_1: 2;
    
      then
    
      
    
    A54: (o9,a19,a39) 
    are_collinear by 
    A6,
    A27,
    Th10;
    
      
    
      
    
    A55: a2 
    on B3 by 
    A14,
    INCSP_1: 2;
    
      then (o9,a19,a29)
    are_collinear by 
    A6,
    A27,
    Th10;
    
      then (c19,c29,c39)
    are_collinear by 
    A1,
    A44,
    A21,
    A43,
    A20,
    A25,
    A28,
    A54,
    A37,
    A42,
    A18,
    A34,
    A24,
    A52,
    A47,
    A40;
    
      then
    
      
    
    A56: ex K be 
    LINE of ( 
    IncProjSp_of CPS) st c1 
    on K & c2 
    on K & c3 
    on K by 
    Th10;
    
      
    
      
    
    A57: o 
    <> a3 by 
    A2,
    ZFMISC_1:def 6;
    
      
    
      
    
    A58: c1 
    <> c2 
    
      proof
    
        assume
    
        
    
    A59: not thesis; 
    
         not a3
    on A3 by 
    A4,
    A5,
    A6,
    A57,
    A53,
    Th8;
    
        then B1
    <> B2 by 
    A48,
    A35,
    A51,
    A39,
    A16,
    A36,
    Th8;
    
        then
    
        
    
    A60: c1 
    = a3 by 
    A35,
    A45,
    A38,
    A59,
    Th8;
    
         not b3
    on B3 by 
    A4,
    A5,
    A6,
    A50,
    A41,
    Th8;
    
        then A1
    <> A2 by 
    A49,
    A46,
    A26,
    A23,
    A27,
    A55,
    Th8;
    
        then c1
    = b3 by 
    A26,
    A19,
    A22,
    A59,
    Th8;
    
        hence contradiction by
    A4,
    A5,
    A6,
    A50,
    A41,
    A53,
    A60,
    Th8;
    
      end;
    
      c1
    on C3 & c2 
    on C3 by 
    A15,
    INCSP_1: 1;
    
      hence thesis by
    A58,
    A56,
    Th8;
    
    end;
    
    definition
    
      let S be
    IncProjStr;
    
      :: 
    
    INCPROJ:def4
    
      attr S is
    
    partial means for p,q be 
    POINT of S, P,Q be 
    LINE of S st p 
    on P & q 
    on P & p 
    on Q & q 
    on Q holds p 
    = q or P 
    = Q; 
    
      :: original:
    linear
    
      redefine
    
      :: 
    
    INCPROJ:def5
    
      attr S is
    
    linear means for p,q be 
    POINT of S holds ex P be 
    LINE of S st p 
    on P & q 
    on P; 
    
      compatibility
    
      proof
    
        hereby
    
          assume
    
          
    
    A1: S is 
    linear;
    
          let p,q be
    POINT of S; 
    
          consider P be
    LINE of S such that 
    
          
    
    A2: 
    {p, q}
    on P by 
    A1;
    
          take P;
    
          thus p
    on P & q 
    on P by 
    A2,
    INCSP_1: 1;
    
        end;
    
        assume
    
        
    
    A3: for p,q be 
    POINT of S holds ex P be 
    LINE of S st p 
    on P & q 
    on P; 
    
        let p,q be
    POINT of S; 
    
        consider L be
    LINE of S such that 
    
        
    
    A4: p 
    on L & q 
    on L by 
    A3;
    
        
    {p, q}
    on L by 
    A4,
    INCSP_1: 1;
    
        hence thesis;
    
      end;
    
    end
    
    definition
    
      let S be
    IncProjStr;
    
      :: 
    
    INCPROJ:def6
    
      attr S is
    
    up-2-dimensional means ex p be 
    POINT of S, P be 
    LINE of S st not p 
    on P; 
    
      :: 
    
    INCPROJ:def7
    
      attr S is
    
    up-3-rank means for P be 
    LINE of S holds ex a,b,c be 
    POINT of S st a 
    <> b & b 
    <> c & c 
    <> a & a 
    on P & b 
    on P & c 
    on P; 
    
      :: 
    
    INCPROJ:def8
    
      attr S is
    
    Vebleian means for a,b,c,d,p,q be 
    POINT of S holds for M,N,P,Q be 
    LINE of S st a 
    on M & b 
    on M & c 
    on N & d 
    on N & p 
    on M & p 
    on N & a 
    on P & c 
    on P & b 
    on Q & d 
    on Q & not p 
    on P & not p 
    on Q & M 
    <> N holds ex q be 
    POINT of S st q 
    on P & q 
    on Q; 
    
    end
    
    registration
    
      let CPS be
    CollProjectiveSpace;
    
      cluster ( 
    IncProjSp_of CPS) -> 
    partial
    linear
    up-2-dimensional
    up-3-rank
    Vebleian;
    
      coherence by
    Th13,
    Th11,
    Th12,
    Th8,
    Th9;
    
    end
    
    registration
    
      cluster 
    strict
    partial
    linear
    up-2-dimensional
    up-3-rank
    Vebleian for 
    IncProjStr;
    
      existence
    
      proof
    
        set CPS = the
    CollProjectiveSpace;
    
        (
    IncProjSp_of CPS) is 
    strict
    partial
    linear
    up-2-dimensional
    up-3-rank
    Vebleian;
    
        hence thesis;
    
      end;
    
    end
    
    definition
    
      mode
    
    IncProjSp is 
    partial
    linear
    up-2-dimensional
    up-3-rank
    Vebleian  
    IncProjStr;
    
    end
    
    registration
    
      let CPS be
    CollProjectiveSpace;
    
      cluster ( 
    IncProjSp_of CPS) -> 
    partial
    linear
    up-2-dimensional
    up-3-rank
    Vebleian;
    
      coherence ;
    
    end
    
    definition
    
      let IT be
    IncProjSp;
    
      :: 
    
    INCPROJ:def9
    
      attr IT is
    
    2-dimensional means for M,N be 
    LINE of IT holds ex q be 
    POINT of IT st q 
    on M & q 
    on N; 
    
    end
    
    notation
    
      let IT be
    IncProjSp;
    
      antonym IT is 
    
    up-3-dimensional for IT is 
    2-dimensional;
    
    end
    
    definition
    
      let IT be
    IncProjStr;
    
      :: 
    
    INCPROJ:def10
    
      attr IT is
    
    at_most-3-dimensional means for a be 
    POINT of IT, M,N be 
    LINE of IT holds ex b,c be 
    POINT of IT, S be 
    LINE of IT st a 
    on S & b 
    on S & c 
    on S & b 
    on M & c 
    on N; 
    
    end
    
    definition
    
      let IT be
    IncProjSp;
    
      :: 
    
    INCPROJ:def11
    
      attr IT is
    
    3-dimensional means IT is 
    at_most-3-dimensional
    up-3-dimensional;
    
    end
    
    definition
    
      let IT be
    IncProjStr;
    
      :: 
    
    INCPROJ:def12
    
      attr IT is
    
    Fanoian means for p,q,r,s,a,b,c be 
    POINT of IT holds for L,Q,R,S,A,B,C be 
    LINE of IT st not q 
    on L & not r 
    on L & not p 
    on Q & not s 
    on Q & not p 
    on R & not r 
    on R & not q 
    on S & not s 
    on S & 
    {a, p, s}
    on L & 
    {a, q, r}
    on Q & 
    {b, q, s}
    on R & 
    {b, p, r}
    on S & 
    {c, p, q}
    on A & 
    {c, r, s}
    on B & 
    {a, b}
    on C holds not c 
    on C; 
    
    end
    
    definition
    
      let IT be
    IncProjStr;
    
      :: 
    
    INCPROJ:def13
    
      attr IT is
    
    Desarguesian means for o,b1,a1,b2,a2,b3,a3,r,s,t be 
    POINT of IT holds for C1,C2,C3,A1,A2,A3,B1,B2,B3 be 
    LINE of IT st 
    {o, b1, a1}
    on C1 & 
    {o, a2, b2}
    on C2 & 
    {o, a3, b3}
    on C3 & 
    {a3, a2, t}
    on A1 & 
    {a3, r, a1}
    on A2 & 
    {a2, s, a1}
    on A3 & 
    {t, b2, b3}
    on B1 & 
    {b1, r, b3}
    on B2 & 
    {b1, s, b2}
    on B3 & (C1,C2,C3) 
    are_mutually_distinct & o 
    <> a1 & o 
    <> a2 & o 
    <> a3 & o 
    <> b1 & o 
    <> b2 & o 
    <> b3 & a1 
    <> b1 & a2 
    <> b2 & a3 
    <> b3 holds ex O be 
    LINE of IT st 
    {r, s, t}
    on O; 
    
    end
    
    definition
    
      let IT be
    IncProjStr;
    
      :: 
    
    INCPROJ:def14
    
      attr IT is
    
    Pappian means for o,a1,a2,a3,b1,b2,b3,c1,c2,c3 be 
    POINT of IT holds for A1,A2,A3,B1,B2,B3,C1,C2,C3 be 
    LINE of IT st (o,a1,a2,a3) 
    are_mutually_distinct & (o,b1,b2,b3) 
    are_mutually_distinct & A3 
    <> B3 & o 
    on A3 & o 
    on B3 & 
    {a2, b3, c1}
    on A1 & 
    {a3, b1, c2}
    on B1 & 
    {a1, b2, c3}
    on C1 & 
    {a1, b3, c2}
    on A2 & 
    {a3, b2, c1}
    on B2 & 
    {a2, b1, c3}
    on C2 & 
    {b1, b2, b3}
    on A3 & 
    {a1, a2, a3}
    on B3 & 
    {c1, c2}
    on C3 holds c3 
    on C3; 
    
    end
    
    registration
    
      cluster 
    Desarguesian
    Fanoian
    at_most-3-dimensional
    up-3-dimensional for 
    IncProjSp;
    
      existence
    
      proof
    
        set CPS = the
    Fanoian
    Desarguesian
    at_most-3-dimensional
    up-3-dimensional  
    CollProjectiveSpace;
    
        reconsider CPS9 = CPS as
    CollProjectiveSpace;
    
        take X = (
    IncProjSp_of CPS9); 
    
        for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be
    Point of CPS9 st o 
    <> q1 & p1 
    <> q1 & o 
    <> q2 & p2 
    <> q2 & o 
    <> q3 & p3 
    <> q3 & not (o,p1,p2) 
    are_collinear & not (o,p1,p3) 
    are_collinear & not (o,p2,p3) 
    are_collinear & (p1,p2,r3) 
    are_collinear & (q1,q2,r3) 
    are_collinear & (p2,p3,r1) 
    are_collinear & (q2,q3,r1) 
    are_collinear & (p1,p3,r2) 
    are_collinear & (q1,q3,r2) 
    are_collinear & (o,p1,q1) 
    are_collinear & (o,p2,q2) 
    are_collinear & (o,p3,q3) 
    are_collinear holds (r1,r2,r3) 
    are_collinear by 
    ANPROJ_2:def 12;
    
        then
    
        
    
    A1: for o,b1,a1,b2,a2,b3,a3,r,s,t be 
    POINT of X holds for C1,C2,C3,A1,A2,A3,B1,B2,B3 be 
    LINE of X st 
    {o, b1, a1}
    on C1 & 
    {o, a2, b2}
    on C2 & 
    {o, a3, b3}
    on C3 & 
    {a3, a2, t}
    on A1 & 
    {a3, r, a1}
    on A2 & 
    {a2, s, a1}
    on A3 & 
    {t, b2, b3}
    on B1 & 
    {b1, r, b3}
    on B2 & 
    {b1, s, b2}
    on B3 & (C1,C2,C3) 
    are_mutually_distinct & o 
    <> a1 & o 
    <> a2 & o 
    <> a3 & o 
    <> b1 & o 
    <> b2 & o 
    <> b3 & a1 
    <> b1 & a2 
    <> b2 & a3 
    <> b3 holds ex O be 
    LINE of X st 
    {r, s, t}
    on O by 
    Th18;
    
        ex p,p1,r,r1 be
    Point of CPS9 st not ex s be 
    Point of CPS9 st ((p,p1,s) 
    are_collinear & (r,r1,s) 
    are_collinear ) by 
    ANPROJ_2:def 14;
    
        then
    
        
    
    A2: ex M,N be 
    LINE of X st not ex q be 
    POINT of X st q 
    on M & q 
    on N by 
    Th15;
    
        for p,p1,q,q1,r2 be
    Point of CPS9 holds ex r,r1 be 
    Point of CPS9 st (p,q,r) 
    are_collinear & (p1,q1,r1) 
    are_collinear & (r2,r,r1) 
    are_collinear by 
    ANPROJ_2:def 15;
    
        then
    
        
    
    A3: for a be 
    POINT of X, M,N be 
    LINE of X holds ex b,c be 
    POINT of X, S be 
    LINE of X st a 
    on S & b 
    on S & c 
    on S & b 
    on M & c 
    on N by 
    Th16;
    
        for p1,r2,q,r1,q1,p,r be
    Point of CPS9 holds ((p1,r2,q) 
    are_collinear & (r1,q1,q) 
    are_collinear & (p1,r1,p) 
    are_collinear & (r2,q1,p) 
    are_collinear & (p1,q1,r) 
    are_collinear & (r2,r1,r) 
    are_collinear & (p,q,r) 
    are_collinear implies ((p1,r2,q1) 
    are_collinear or (p1,r2,r1) 
    are_collinear or (p1,r1,q1) 
    are_collinear or (r2,r1,q1) 
    are_collinear )) by 
    ANPROJ_2:def 11;
    
        then for p,q,r,s,a,b,c be
    POINT of X holds for L,Q,R,S,A,B,C be 
    LINE of X st not q 
    on L & not r 
    on L & not p 
    on Q & not s 
    on Q & not p 
    on R & not r 
    on R & not q 
    on S & not s 
    on S & 
    {a, p, s}
    on L & 
    {a, q, r}
    on Q & 
    {b, q, s}
    on R & 
    {b, p, r}
    on S & 
    {c, p, q}
    on A & 
    {c, r, s}
    on B & 
    {a, b}
    on C holds not c 
    on C by 
    Th17;
    
        hence thesis by
    A1,
    A2,
    A3;
    
      end;
    
    end
    
    registration
    
      cluster 
    Pappian
    Fanoian
    at_most-3-dimensional
    up-3-dimensional for 
    IncProjSp;
    
      existence
    
      proof
    
        set CPS = the
    Fanoian
    Pappian
    at_most-3-dimensional
    up-3-dimensional  
    CollProjectiveSpace;
    
        reconsider CPS9 = CPS as
    CollProjectiveSpace;
    
        take X = (
    IncProjSp_of CPS9); 
    
        for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be
    Point of CPS9 st o 
    <> p2 & o 
    <> p3 & p2 
    <> p3 & p1 
    <> p2 & p1 
    <> p3 & o 
    <> q2 & o 
    <> q3 & q2 
    <> q3 & q1 
    <> q2 & q1 
    <> q3 & not (o,p1,q1) 
    are_collinear & (o,p1,p2) 
    are_collinear & (o,p1,p3) 
    are_collinear & (o,q1,q2) 
    are_collinear & (o,q1,q3) 
    are_collinear & (p1,q2,r3) 
    are_collinear & (q1,p2,r3) 
    are_collinear & (p1,q3,r2) 
    are_collinear & (p3,q1,r2) 
    are_collinear & (p2,q3,r1) 
    are_collinear & (p3,q2,r1) 
    are_collinear holds (r1,r2,r3) 
    are_collinear by 
    ANPROJ_2:def 13;
    
        then
    
        
    
    A1: for o,a1,a2,a3,b1,b2,b3,c1,c2,c3 be 
    POINT of X holds for A1,A2,A3,B1,B2,B3,C1,C2,C3 be 
    LINE of X st (o,a1,a2,a3) 
    are_mutually_distinct & (o,b1,b2,b3) 
    are_mutually_distinct & A3 
    <> B3 & o 
    on A3 & o 
    on B3 & 
    {a2, b3, c1}
    on A1 & 
    {a3, b1, c2}
    on B1 & 
    {a1, b2, c3}
    on C1 & 
    {a1, b3, c2}
    on A2 & 
    {a3, b2, c1}
    on B2 & 
    {a2, b1, c3}
    on C2 & 
    {b1, b2, b3}
    on A3 & 
    {a1, a2, a3}
    on B3 & 
    {c1, c2}
    on C3 holds c3 
    on C3 by 
    Th19;
    
        ex p,p1,r,r1 be
    Point of CPS9 st not ex s be 
    Point of CPS9 st ((p,p1,s) 
    are_collinear & (r,r1,s) 
    are_collinear ) by 
    ANPROJ_2:def 14;
    
        then
    
        
    
    A2: ex M,N be 
    LINE of X st not ex q be 
    POINT of X st q 
    on M & q 
    on N by 
    Th15;
    
        for p,p1,q,q1,r2 be
    Point of CPS9 holds ex r,r1 be 
    Point of CPS9 st (p,q,r) 
    are_collinear & (p1,q1,r1) 
    are_collinear & (r2,r,r1) 
    are_collinear by 
    ANPROJ_2:def 15;
    
        then
    
        
    
    A3: for a be 
    POINT of X, M,N be 
    LINE of X holds ex b,c be 
    POINT of X, S be 
    LINE of X st a 
    on S & b 
    on S & c 
    on S & b 
    on M & c 
    on N by 
    Th16;
    
        for p1,r2,q,r1,q1,p,r be
    Point of CPS9 holds ((p1,r2,q) 
    are_collinear & (r1,q1,q) 
    are_collinear & (p1,r1,p) 
    are_collinear & (r2,q1,p) 
    are_collinear & (p1,q1,r) 
    are_collinear & (r2,r1,r) 
    are_collinear & (p,q,r) 
    are_collinear implies ((p1,r2,q1) 
    are_collinear or (p1,r2,r1) 
    are_collinear or (p1,r1,q1) 
    are_collinear or (r2,r1,q1) 
    are_collinear )) by 
    ANPROJ_2:def 11;
    
        then for p,q,r,s,a,b,c be
    POINT of X holds for L,Q,R,S,A,B,C be 
    LINE of X st not q 
    on L & not r 
    on L & not p 
    on Q & not s 
    on Q & not p 
    on R & not r 
    on R & not q 
    on S & not s 
    on S & 
    {a, p, s}
    on L & 
    {a, q, r}
    on Q & 
    {b, q, s}
    on R & 
    {b, p, r}
    on S & 
    {c, p, q}
    on A & 
    {c, r, s}
    on B & 
    {a, b}
    on C holds not c 
    on C by 
    Th17;
    
        hence thesis by
    A1,
    A2,
    A3;
    
      end;
    
    end
    
    registration
    
      cluster 
    Desarguesian
    Fanoian
    2-dimensional for 
    IncProjSp;
    
      existence
    
      proof
    
        set CPS = the
    Fanoian
    Desarguesian  
    CollProjectivePlane;
    
        reconsider CPS9 = CPS as
    CollProjectiveSpace;
    
        take X = (
    IncProjSp_of CPS9); 
    
        for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be
    Point of CPS9 st o 
    <> q1 & p1 
    <> q1 & o 
    <> q2 & p2 
    <> q2 & o 
    <> q3 & p3 
    <> q3 & not (o,p1,p2) 
    are_collinear & not (o,p1,p3) 
    are_collinear & not (o,p2,p3) 
    are_collinear & (p1,p2,r3) 
    are_collinear & (q1,q2,r3) 
    are_collinear & (p2,p3,r1) 
    are_collinear & (q2,q3,r1) 
    are_collinear & (p1,p3,r2) 
    are_collinear & (q1,q3,r2) 
    are_collinear & (o,p1,q1) 
    are_collinear & (o,p2,q2) 
    are_collinear & (o,p3,q3) 
    are_collinear holds (r1,r2,r3) 
    are_collinear by 
    ANPROJ_2:def 12;
    
        then
    
        
    
    A1: for o,b1,a1,b2,a2,b3,a3,r,s,t be 
    POINT of X holds for C1,C2,C3,A1,A2,A3,B1,B2,B3 be 
    LINE of X st 
    {o, b1, a1}
    on C1 & 
    {o, a2, b2}
    on C2 & 
    {o, a3, b3}
    on C3 & 
    {a3, a2, t}
    on A1 & 
    {a3, r, a1}
    on A2 & 
    {a2, s, a1}
    on A3 & 
    {t, b2, b3}
    on B1 & 
    {b1, r, b3}
    on B2 & 
    {b1, s, b2}
    on B3 & (C1,C2,C3) 
    are_mutually_distinct & o 
    <> a1 & o 
    <> a2 & o 
    <> a3 & o 
    <> b1 & o 
    <> b2 & o 
    <> b3 & a1 
    <> b1 & a2 
    <> b2 & a3 
    <> b3 holds ex O be 
    LINE of X st 
    {r, s, t}
    on O by 
    Th18;
    
        for a,b,c,d be
    Point of CPS9 holds ex p be 
    Point of CPS9 st (a,b,p) 
    are_collinear & (c,d,p) 
    are_collinear by 
    ANPROJ_2:def 14;
    
        then
    
        
    
    A2: for M,N be 
    LINE of X holds ex q be 
    POINT of X st q 
    on M & q 
    on N by 
    Th14;
    
        for p1,r2,q,r1,q1,p,r be
    Point of CPS9 holds ((p1,r2,q) 
    are_collinear & (r1,q1,q) 
    are_collinear & (p1,r1,p) 
    are_collinear & (r2,q1,p) 
    are_collinear & (p1,q1,r) 
    are_collinear & (r2,r1,r) 
    are_collinear & (p,q,r) 
    are_collinear implies ((p1,r2,q1) 
    are_collinear or (p1,r2,r1) 
    are_collinear or (p1,r1,q1) 
    are_collinear or (r2,r1,q1) 
    are_collinear )) by 
    ANPROJ_2:def 11;
    
        then for p,q,r,s,a,b,c be
    POINT of X holds for L,Q,R,S,A,B,C be 
    LINE of X st not q 
    on L & not r 
    on L & not p 
    on Q & not s 
    on Q & not p 
    on R & not r 
    on R & not q 
    on S & not s 
    on S & 
    {a, p, s}
    on L & 
    {a, q, r}
    on Q & 
    {b, q, s}
    on R & 
    {b, p, r}
    on S & 
    {c, p, q}
    on A & 
    {c, r, s}
    on B & 
    {a, b}
    on C holds not c 
    on C by 
    Th17;
    
        hence thesis by
    A1,
    A2;
    
      end;
    
    end
    
    registration
    
      cluster 
    Pappian
    Fanoian
    2-dimensional for 
    IncProjSp;
    
      existence
    
      proof
    
        set CPS = the
    Fanoian
    Pappian  
    CollProjectivePlane;
    
        reconsider CPS9 = CPS as
    CollProjectiveSpace;
    
        take X = (
    IncProjSp_of CPS9); 
    
        for o,p1,p2,p3,q1,q2,q3,r1,r2,r3 be
    Point of CPS9 st o 
    <> p2 & o 
    <> p3 & p2 
    <> p3 & p1 
    <> p2 & p1 
    <> p3 & o 
    <> q2 & o 
    <> q3 & q2 
    <> q3 & q1 
    <> q2 & q1 
    <> q3 & not (o,p1,q1) 
    are_collinear & (o,p1,p2) 
    are_collinear & (o,p1,p3) 
    are_collinear & (o,q1,q2) 
    are_collinear & (o,q1,q3) 
    are_collinear & (p1,q2,r3) 
    are_collinear & (q1,p2,r3) 
    are_collinear & (p1,q3,r2) 
    are_collinear & (p3,q1,r2) 
    are_collinear & (p2,q3,r1) 
    are_collinear & (p3,q2,r1) 
    are_collinear holds (r1,r2,r3) 
    are_collinear by 
    ANPROJ_2:def 13;
    
        then
    
        
    
    A1: for o,a1,a2,a3,b1,b2,b3,c1,c2,c3 be 
    POINT of X holds for A1,A2,A3,B1,B2,B3,C1,C2,C3 be 
    LINE of X st (o,a1,a2,a3) 
    are_mutually_distinct & (o,b1,b2,b3) 
    are_mutually_distinct & A3 
    <> B3 & o 
    on A3 & o 
    on B3 & 
    {a2, b3, c1}
    on A1 & 
    {a3, b1, c2}
    on B1 & 
    {a1, b2, c3}
    on C1 & 
    {a1, b3, c2}
    on A2 & 
    {a3, b2, c1}
    on B2 & 
    {a2, b1, c3}
    on C2 & 
    {b1, b2, b3}
    on A3 & 
    {a1, a2, a3}
    on B3 & 
    {c1, c2}
    on C3 holds c3 
    on C3 by 
    Th19;
    
        for a,b,c,d be
    Point of CPS9 holds ex p be 
    Point of CPS9 st (a,b,p) 
    are_collinear & (c,d,p) 
    are_collinear by 
    ANPROJ_2:def 14;
    
        then
    
        
    
    A2: for M,N be 
    LINE of X holds ex q be 
    POINT of X st q 
    on M & q 
    on N by 
    Th14;
    
        for p1,r2,q,r1,q1,p,r be
    Point of CPS9 holds ((p1,r2,q) 
    are_collinear & (r1,q1,q) 
    are_collinear & (p1,r1,p) 
    are_collinear & (r2,q1,p) 
    are_collinear & (p1,q1,r) 
    are_collinear & (r2,r1,r) 
    are_collinear & (p,q,r) 
    are_collinear implies ((p1,r2,q1) 
    are_collinear or (p1,r2,r1) 
    are_collinear or (p1,r1,q1) 
    are_collinear or (r2,r1,q1) 
    are_collinear )) by 
    ANPROJ_2:def 11;
    
        then for p,q,r,s,a,b,c be
    POINT of X holds for L,Q,R,S,A,B,C be 
    LINE of X st not q 
    on L & not r 
    on L & not p 
    on Q & not s 
    on Q & not p 
    on R & not r 
    on R & not q 
    on S & not s 
    on S & 
    {a, p, s}
    on L & 
    {a, q, r}
    on Q & 
    {b, q, s}
    on R & 
    {b, p, r}
    on S & 
    {c, p, q}
    on A & 
    {c, r, s}
    on B & 
    {a, b}
    on C holds not c 
    on C by 
    Th17;
    
        hence thesis by
    A1,
    A2;
    
      end;
    
    end