pascal.miz



    begin

    reserve n for Nat;

    reserve K for Field;

    reserve a,b,c,d,e,f,g,h,i,a1,b1,c1,d1,e1,f1,g1,h1,i1 for Element of K;

    reserve M,N for Matrix of 3, K;

    reserve p for FinSequence of REAL ;

    theorem :: PASCAL:1

    

     Th01: for p,q,r be Point of ( TOP-REAL 3) holds |{p, q, r}| = |{r, p, q}| & |{p, q, r}| = |{q, r, p}|

    proof

      let p,q,r be Point of ( TOP-REAL 3);

      

      thus |{p, q, r}| = ( - |{p, r, q}|) by ANPROJ_8: 29

      .= |{r, p, q}| by ANPROJ_8: 30;

      

      thus |{p, q, r}| = ( - |{q, p, r}|) by ANPROJ_8: 30

      .= |{q, r, p}| by ANPROJ_8: 29;

    end;

    theorem :: PASCAL:2

    

     Th02: <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> = <* <*a1, b1, c1*>, <*d1, e1, f1*>, <*g1, h1, i1*>*> implies a = a1 & b = b1 & c = c1 & d = d1 & e = e1 & f = f1 & g = g1 & h = h1 & i = i1

    proof

      assume <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> = <* <*a1, b1, c1*>, <*d1, e1, f1*>, <*g1, h1, i1*>*>;

      then <*a, b, c*> = <*a1, b1, c1*> & <*d, e, f*> = <*d1, e1, f1*> & <*g, h, i*> = <*g1, h1, i1*> by FINSEQ_1: 78;

      hence thesis by FINSEQ_1: 78;

    end;

    theorem :: PASCAL:3

    

     Th03: ex a, b, c, d, e, f, g, h, i st M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>

    proof

      reconsider a = (M * (1,1)), b = (M * (1,2)), c = (M * (1,3)), d = (M * (2,1)), e = (M * (2,2)), f = (M * (2,3)), g = (M * (3,1)), h = (M * (3,2)), i = (M * (3,3)) as Element of K;

      take a, b, c, d, e, f, g, h, i;

      thus thesis by MATRIXR2: 37;

    end;

    theorem :: PASCAL:4

    

     Th04: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies a = (M * (1,1)) & b = (M * (1,2)) & c = (M * (1,3)) & d = (M * (2,1)) & e = (M * (2,2)) & f = (M * (2,3)) & g = (M * (3,1)) & h = (M * (3,2)) & i = (M * (3,3))

    proof

      assume M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      then

       A1: (M . 1) = <*a, b, c*> & (M . 2) = <*d, e, f*> & (M . 3) = <*g, h, i*> by FINSEQ_1: 45;

      

       A2: [1, 1] in ( Indices M) & [1, 2] in ( Indices M) & [1, 3] in ( Indices M) & [2, 1] in ( Indices M) & [2, 2] in ( Indices M) & [2, 3] in ( Indices M) & [3, 1] in ( Indices M) & [3, 2] in ( Indices M) & [3, 3] in ( Indices M) by MATRIX_0: 24, ANPROJ_8: 1;

      then ex s be FinSequence of K st s = (M . 1) & (M * (1,1)) = (s . 1) by MATRIX_0:def 5;

      hence (M * (1,1)) = a by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 1) & (M * (1,2)) = (s . 2) by A2, MATRIX_0:def 5;

      hence (M * (1,2)) = b by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 1) & (M * (1,3)) = (s . 3) by A2, MATRIX_0:def 5;

      hence (M * (1,3)) = c by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 2) & (M * (2,1)) = (s . 1) by A2, MATRIX_0:def 5;

      hence (M * (2,1)) = d by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 2) & (M * (2,2)) = (s . 2) by A2, MATRIX_0:def 5;

      hence (M * (2,2)) = e by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 2) & (M * (2,3)) = (s . 3) by A2, MATRIX_0:def 5;

      hence (M * (2,3)) = f by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 3) & (M * (3,1)) = (s . 1) by A2, MATRIX_0:def 5;

      hence (M * (3,1)) = g by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 3) & (M * (3,2)) = (s . 2) by A2, MATRIX_0:def 5;

      hence (M * (3,2)) = h by A1, FINSEQ_1: 45;

      ex s be FinSequence of K st s = (M . 3) & (M * (3,3)) = (s . 3) by A2, MATRIX_0:def 5;

      hence (M * (3,3)) = i by A1, FINSEQ_1: 45;

    end;

    theorem :: PASCAL:5

    

     Th05: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies (M @ ) = <* <*a, d, g*>, <*b, e, h*>, <*c, f, i*>*>

    proof

      assume M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      then

       A1: a = (M * (1,1)) & b = (M * (1,2)) & c = (M * (1,3)) & d = (M * (2,1)) & e = (M * (2,2)) & f = (M * (2,3)) & g = (M * (3,1)) & h = (M * (3,2)) & i = (M * (3,3)) by Th04;

      consider ap,bp,cp,dp,ep,fp,gp,hp,ip be Element of K such that

       A2: (M @ ) = <* <*ap, bp, cp*>, <*dp, ep, fp*>, <*gp, hp, ip*>*> by Th03;

      

       A3: ap = ((M @ ) * (1,1)) & bp = ((M @ ) * (1,2)) & cp = ((M @ ) * (1,3)) & dp = ((M @ ) * (2,1)) & ep = ((M @ ) * (2,2)) & fp = ((M @ ) * (2,3)) & gp = ((M @ ) * (3,1)) & hp = ((M @ ) * (3,2)) & ip = ((M @ ) * (3,3)) by A2, Th04;

       [1, 1] in ( Indices M) & [1, 2] in ( Indices M) & [1, 3] in ( Indices M) & [2, 1] in ( Indices M) & [2, 2] in ( Indices M) & [2, 3] in ( Indices M) & [3, 1] in ( Indices M) & [3, 2] in ( Indices M) & [3, 3] in ( Indices M) by MATRIX_0: 24, ANPROJ_8: 1;

      then (M * (1,1)) = ((M @ ) * (1,1)) & (M * (1,2)) = ((M @ ) * (2,1)) & (M * (1,3)) = ((M @ ) * (3,1)) & (M * (2,1)) = ((M @ ) * (1,2)) & (M * (2,2)) = ((M @ ) * (2,2)) & (M * (2,3)) = ((M @ ) * (3,2)) & (M * (3,1)) = ((M @ ) * (1,3)) & (M * (3,2)) = ((M @ ) * (2,3)) & (M * (3,3)) = ((M @ ) * (3,3)) by MATRIX_0:def 6;

      hence thesis by A2, A1, A3;

    end;

    theorem :: PASCAL:6

    

     Th06: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> & M is symmetric implies b = d & c = g & h = f

    proof

      assume that

       A1: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> and

       A2: M is symmetric;

      

       A3: M = (M @ ) by A2, MATRIX_6:def 5;

      (M @ ) = <* <*a, d, g*>, <*b, e, h*>, <*c, f, i*>*> by A1, Th05;

      hence thesis by A1, A3, Th02;

    end;

    theorem :: PASCAL:7

    

     Th07: for M,N be Matrix of 3, F_Real st N is symmetric holds (((M @ ) * N) * M) is symmetric

    proof

      let M,N be Matrix of 3, F_Real ;

      assume

       A1: N is symmetric;

      

       A2: ( len N) = 3 & ( width N) = 3 & ( len M) = 3 & ( width M) = 3 by MATRIX_0: 24;

      then

       A3: ( width (M @ )) = ( len N) & ( width N) = ( len M) by MATRIX_0: 29;

      ( width (M @ )) = ( len N) & ( width N) <> 0 by A2, MATRIX_0: 29;

      

      then

       A4: (((M @ ) * N) @ ) = ((N @ ) * ((M @ ) @ )) by MATRIX_3: 22

      .= ((N @ ) * M) by A2, MATRIX_0: 57;

      ( width ((M @ ) * N)) = ( len M) & ( width M) <> 0 by MATRIX_0: 24, A2;

      

      then ((((M @ ) * N) * M) @ ) = ((M @ ) * (((M @ ) * N) @ )) by MATRIX_3: 22

      .= ((M @ ) * (N * M)) by A4, A1, MATRIX_6:def 5

      .= (((M @ ) * N) * M) by A3, MATRIX_3: 33;

      hence thesis by MATRIX_6:def 5;

    end;

    theorem :: PASCAL:8

    

     Th08: for M be Matrix of 3, F_Real holds for a,b,c,d,e,f,g,h,i,x,y,z be Element of F_Real holds for v be Element of ( TOP-REAL 3) holds for uf be FinSequence of F_Real holds for p be FinSequence of (1 -tuples_on REAL ) st p = (M * uf) & v = ( M2F p) & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> & uf = <*x, y, z*> holds p = <* <*(((a * x) + (b * y)) + (c * z))*>, <*(((d * x) + (e * y)) + (f * z))*>, <*(((g * x) + (h * y)) + (i * z))*>*> & v = <*(((a * x) + (b * y)) + (c * z)), (((d * x) + (e * y)) + (f * z)), (((g * x) + (h * y)) + (i * z))*>

    proof

      let M be Matrix of 3, F_Real ;

      let a,b,c,d,e,f,g,h,i,x,y,z be Element of F_Real ;

      let v be Element of ( TOP-REAL 3);

      let uf be FinSequence of F_Real ;

      let p be FinSequence of (1 -tuples_on REAL );

      assume

       A1: p = (M * uf) & v = ( M2F p) & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> & uf = <*x, y, z*>;

      then

       A2: ( len uf) = 3 by FINSEQ_1: 45;

      

       A3: ( len <*uf*>) = 1 by FINSEQ_1: 39;

      ( rng <*uf*>) = {uf} by FINSEQ_1: 39;

      then uf in ( rng <*uf*>) by TARSKI:def 1;

      then

       A4: ( width <*uf*>) = 3 by A2, A3, MATRIX_0:def 3;

      

      then

       A5: ( width ( <*uf*> @ )) = ( len <*uf*>) by MATRIX_0: 29

      .= 1 by FINSEQ_1: 39;

      ( len ( <*uf*> @ )) = 3 by MATRIX_0:def 6, A4;

      then

       A6: ( <*uf*> @ ) is Matrix of 3, 1, F_Real by A5, MATRIX_0: 20;

      (uf . 1) = x & (uf . 2) = y & (uf . 3) = z by A1, FINSEQ_1: 45;

      then

       A8: ( <*uf*> @ ) = <* <*x*>, <*y*>, <*z*>*> by A2, ANPROJ_8: 77;

      

      thus

       A9: p = (M * ( <*uf*> @ )) by A1, LAPLACE:def 9

      .= <* <*(((a * x) + (b * y)) + (c * z))*>, <*(((d * x) + (e * y)) + (f * z))*>, <*(((g * x) + (h * y)) + (i * z))*>*> by A1, A8, A6, ANPROJ_9: 7;

      now

        thus ( len p) = 3 by A9, FINSEQ_1: 45;

        (p . 1) = <*(((a * x) + (b * y)) + (c * z))*> by A9, FINSEQ_1: 45;

        hence ((p . 1) . 1) = (((a * x) + (b * y)) + (c * z)) by FINSEQ_1: 40;

        (p . 2) = <*(((d * x) + (e * y)) + (f * z))*> by A9, FINSEQ_1: 45;

        hence ((p . 2) . 1) = (((d * x) + (e * y)) + (f * z)) by FINSEQ_1: 40;

        (p . 3) = <*(((g * x) + (h * y)) + (i * z))*> by A9, FINSEQ_1: 45;

        hence ((p . 3) . 1) = (((g * x) + (h * y)) + (i * z)) by FINSEQ_1: 40;

      end;

      hence thesis by A1, ANPROJ_8:def 2;

    end;

    

     Lm01: for N1,M,N2 be Matrix of 3, REAL st ( len p) = 3 holds (((N1 * M) * N2) * p) = (N1 * (M * (N2 * p)))

    proof

      let N1,M,N2 be Matrix of 3, REAL ;

      assume

       A1: ( len p) = 3;

      

       A2: ( width M) = 3 & ( len M) = 3 & ( width N1) = 3 & ( len N2) = 3 & ( width N2) = 3 by MATRIX_0: 24;

      

       A3: ( len (N2 * p)) = 3 by A1, A2, MATRIXR1: 61;

      

       A4: ( len p) = ( width N2) & ( width (N1 * M)) = ( len N2) & ( len p) > 0 & ( len N2) > 0 by MATRIXR2: 4, A2, A1;

      (N1 * (M * (N2 * p))) = ((N1 * M) * (N2 * p)) by A3, A2, MATRIXR2: 59

      .= (((N1 * M) * N2) * p) by A4, MATRIXR2: 59;

      hence thesis;

    end;

    

     Lm02: for N,M be Matrix of 3, REAL holds ( len p) = 3 implies |((N * p), (M * (N * p)))| = |(p, ((((N @ ) * M) * N) * p))|

    proof

      let N,M be Matrix of 3, REAL ;

      assume

       A1: ( len p) = 3;

      

       A2: ( len N) = 3 by MATRIX_0: 24;

      

       A3: ( len M) = 3 by MATRIX_0: 24;

      

       A4: ( width N) = 3 by MATRIX_0: 24;

      

       A5: ( width M) = 3 by MATRIX_0: 24;

      ( width N) = ( len p) & ( len p) > 0 by A1, MATRIX_0: 24;

      then ( width M) = ( len (N * p)) & ( len (N * p)) > 0 by A2, A4, A5, MATRIXR1: 61;

      then ( len (M * (N * p))) = ( len N) by A2, A3, MATRIXR1: 61;

      

      then |((N * p), (M * (N * p)))| = |(p, ((N @ ) * (M * (N * p))))| by A2, A4, A1, MATRPROB: 48

      .= |(p, ((((N @ ) * M) * N) * p))| by A1, Lm01;

      hence thesis;

    end;

    

     Lm03: for NR,M be Matrix of 3, REAL holds ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M) * ( MXF2MXR (( MXR2MXF NR) ~ ))) is Matrix of 3, REAL

    proof

      let NR,M be Matrix of 3, REAL ;

      now

        reconsider M6 = ( MXF2MXR (( MXR2MXF (NR @ )) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

        (M6 * M) is Matrix of 3, REAL ;

        hence (( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M) is Matrix of 3, REAL ;

        thus ( MXF2MXR (( MXR2MXF NR) ~ )) is Matrix of 3, REAL by MATRIXR1:def 2;

      end;

      then

      reconsider M3 = (( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M), M4 = ( MXF2MXR (( MXR2MXF NR) ~ )) as Matrix of 3, REAL ;

      (M3 * M4) is Matrix of 3, REAL ;

      hence thesis;

    end;

    

     Lm04: for A,B,C,D,E be Matrix of n, REAL holds ((A * ((B * C) * D)) * E) = (((A * B) * C) * (D * E))

    proof

      let A,B,C,D,E be Matrix of n, REAL ;

      ((A * ((B * C) * D)) * E) = ((A * (B * (C * D))) * E) by MATRIXR2: 28

      .= (A * ((B * (C * D)) * E)) by MATRIXR2: 28

      .= (A * (B * ((C * D) * E))) by MATRIXR2: 28

      .= (A * (B * (C * (D * E)))) by MATRIXR2: 28

      .= (A * ((B * C) * (D * E))) by MATRIXR2: 28

      .= ((A * (B * C)) * (D * E)) by MATRIXR2: 28

      .= (((A * B) * C) * (D * E)) by MATRIXR2: 28;

      hence thesis;

    end;

    

     Lm05: for A,B be Matrix of n, F_Real holds ( MXF2MXR (A * B)) = (( MXF2MXR A) * ( MXF2MXR B))

    proof

      let A,B be Matrix of n, F_Real ;

      (( MXF2MXR A) * ( MXF2MXR B)) = ( MXF2MXR (( MXR2MXF ( MXF2MXR A)) * ( MXR2MXF ( MXF2MXR B)))) by MATRIXR1:def 6

      .= ( MXF2MXR (A * ( MXR2MXF ( MXF2MXR B)))) by ANPROJ_8: 16

      .= ( MXF2MXR (A * B)) by ANPROJ_8: 16;

      hence thesis;

    end;

    

     Lm06: for A be Matrix of REAL holds ( MXF2MXR ( MXR2MXF A)) = A

    proof

      let A be Matrix of REAL ;

      ( MXF2MXR ( MXR2MXF A)) = ( MXR2MXF A) by MATRIXR1:def 2

      .= A by MATRIXR1:def 1;

      hence thesis;

    end;

    

     Lm07: for A,B be Matrix of n, REAL holds ( MXR2MXF (A * B)) = (( MXR2MXF A) * ( MXR2MXF B))

    proof

      let A,B be Matrix of n, REAL ;

      (A * B) = (( MXF2MXR ( MXR2MXF A)) * B) by Lm06

      .= (( MXF2MXR ( MXR2MXF A)) * ( MXF2MXR ( MXR2MXF B))) by Lm06

      .= ( MXF2MXR (( MXR2MXF A) * ( MXR2MXF B))) by Lm05;

      hence thesis by ANPROJ_8: 16;

    end;

    

     Lm08: for N be invertible Matrix of 3, F_Real holds for NR be Matrix of 3, REAL st NR = ( MXF2MXR N) holds (NR * ( MXF2MXR (( MXR2MXF NR) ~ ))) = ( 1_Rmatrix 3)

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR be Matrix of 3, REAL ;

      assume

       A1: NR = ( MXF2MXR N);

      

       A2: (N ~ ) is_reverse_of N by MATRIX_6:def 4;

      (NR * ( MXF2MXR (( MXR2MXF NR) ~ ))) = (( MXF2MXR N) * ( MXF2MXR (N ~ ))) by A1, ANPROJ_8: 16

      .= ( MXF2MXR (N * (N ~ ))) by Lm05

      .= ( 1_Rmatrix 3) by A2, MATRIX_6:def 2;

      hence thesis;

    end;

    

     Lm09: for N be invertible Matrix of 3, F_Real holds for NR be Matrix of 3, REAL st NR = ( MXF2MXR N) holds ((NR @ ) * ( MXF2MXR (( MXR2MXF (NR @ )) ~ ))) = ( 1_Rmatrix 3)

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR be Matrix of 3, REAL ;

      assume NR = ( MXF2MXR N);

      then (NR @ ) = (N @ ) by MATRIXR1:def 2;

      then (NR @ ) = ( MXF2MXR (N @ )) by MATRIXR1:def 2;

      hence thesis by Lm08;

    end;

    

     Lm10: for N be invertible Matrix of 3, F_Real holds for NR be Matrix of 3, REAL st NR = ( MXF2MXR N) holds (( MXF2MXR (( MXR2MXF NR) ~ )) * NR) = ( 1_Rmatrix 3)

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR be Matrix of 3, REAL ;

      assume

       A1: NR = ( MXF2MXR N);

      

       A2: (N ~ ) is_reverse_of N by MATRIX_6:def 4;

      (( MXF2MXR (( MXR2MXF NR) ~ )) * NR) = (( MXF2MXR (N ~ )) * ( MXF2MXR N)) by A1, ANPROJ_8: 16

      .= ( MXF2MXR ((N ~ ) * N)) by Lm05

      .= ( 1_Rmatrix 3) by A2, MATRIX_6:def 2;

      hence thesis;

    end;

    

     Lm11: for N be invertible Matrix of 3, F_Real holds for NR be Matrix of 3, REAL st NR = ( MXF2MXR N) holds (( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * (NR @ )) = ( 1_Rmatrix 3)

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR be Matrix of 3, REAL ;

      assume NR = ( MXF2MXR N);

      then (NR @ ) = (N @ ) by MATRIXR1:def 2;

      then (NR @ ) = ( MXF2MXR (N @ )) by MATRIXR1:def 2;

      hence thesis by Lm10;

    end;

    

     Lm12: for N be invertible Matrix of 3, F_Real holds for NR be Matrix of 3, REAL st NR = ( MXF2MXR N) holds (NR @ ) is invertible

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR be Matrix of 3, REAL ;

      assume

       A1: NR = ( MXF2MXR N);

      reconsider C = (( MXR2MXF (NR @ )) ~ ) as Matrix of 3, F_Real ;

      reconsider B = ( MXF2MXR (( MXR2MXF (NR @ )) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

      ((NR @ ) * B) = ( 1_Rmatrix 3) & (B * (NR @ )) = ( 1_Rmatrix 3) by A1, Lm11, Lm09;

      hence thesis;

    end;

    

     Lm13: for N be invertible Matrix of 3, F_Real holds for NR,M,M2 be Matrix of 3, REAL st NR = ( MXF2MXR N) & M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M) * ( MXF2MXR (( MXR2MXF NR) ~ ))) holds (((NR @ ) * M2) * NR) = M

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR,M,M2 be Matrix of 3, REAL ;

      assume that

       A1: NR = ( MXF2MXR N) and

       A2: M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M) * ( MXF2MXR (( MXR2MXF NR) ~ )));

      reconsider NI = ( MXF2MXR (( MXR2MXF NR) ~ )), NJ = ( MXF2MXR (( MXR2MXF (NR @ )) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

      

       A3: (NI * NR) = ( 1_Rmatrix 3) by A1, Lm10;

      (((NR @ ) * M2) * NR) = ((((NR @ ) * NJ) * M) * (NI * NR)) by A2, Lm04

      .= ((( 1_Rmatrix 3) * M) * ( 1_Rmatrix 3)) by A1, Lm09, A3

      .= (M * ( 1_Rmatrix 3)) by MATRIXR2: 70

      .= M by MATRIXR2: 71;

      hence thesis;

    end;

    

     Lm14: for N be invertible Matrix of n, F_Real holds for M be Matrix of n, REAL st M = ( MXF2MXR N) holds M is invertible

    proof

      let N be invertible Matrix of n, F_Real ;

      let M be Matrix of n, REAL ;

      assume

       A1: M = ( MXF2MXR N);

      

       A2: (N ~ ) is_reverse_of N by MATRIX_6:def 4;

      reconsider M2 = ( MXF2MXR (N ~ )) as Matrix of n, REAL by MATRIXR1:def 2;

      now

        thus (M * M2) = ( 1_Rmatrix n)

        proof

          (M * M2) = ( MXF2MXR (N * (N ~ ))) by A1, Lm05

          .= ( 1_Rmatrix n) by A2, MATRIX_6:def 2;

          hence thesis;

        end;

        thus (M2 * M) = ( 1_Rmatrix n)

        proof

          (M2 * M) = ( MXF2MXR ((N ~ ) * N)) by A1, Lm05

          .= ( 1_Rmatrix n) by A2, MATRIX_6:def 2;

          hence thesis;

        end;

      end;

      hence thesis;

    end;

    

     Lm15: for N be Matrix of n, F_Real holds for M be Matrix of n, REAL st M is invertible & N = ( MXR2MXF M) holds N is invertible

    proof

      let N be Matrix of n, F_Real ;

      let M be Matrix of n, REAL ;

      assume that

       A1: M is invertible and

       A2: N = ( MXR2MXF M);

      consider MI be Matrix of n, REAL such that

       A3: (MI * M) = ( 1_Rmatrix n) and

       A4: (M * MI) = ( 1_Rmatrix n) by A1;

      reconsider NI = ( MXR2MXF MI) as Matrix of n, F_Real ;

      now

        

         A5: (N * NI) = ( MXR2MXF (M * MI)) by A2, Lm07

        .= ( 1. ( F_Real ,n)) by A4, ANPROJ_8: 16;

        

         A6: (NI * N) = ( MXR2MXF (MI * M)) by A2, Lm07

        .= ( 1. ( F_Real ,n)) by A3, ANPROJ_8: 16;

        thus (N * NI) = (NI * N) by A5, A6;

        thus (N * NI) = ( 1. ( F_Real ,n)) by A5;

      end;

      hence thesis by MATRIX_6:def 2, MATRIX_6:def 3;

    end;

    theorem :: PASCAL:9

    

     Th09: for M be Matrix of 3, REAL holds for a,b,c,d,e,f,g,h,i,p1,p2,p3 be Element of REAL st M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> & p = <*p1, p2, p3*> holds (M * p) = <*(((a * p1) + (b * p2)) + (c * p3)), (((d * p1) + (e * p2)) + (f * p3)), (((g * p1) + (h * p2)) + (i * p3))*>

    proof

      let M be Matrix of 3, REAL ;

      let a,b,c,d,e,f,g,h,i,p1,p2,p3 be Element of REAL ;

      assume that

       A1: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> and

       A2: p = <*p1, p2, p3*>;

      

       A3: (p . 1) = p1 & (p . 2) = p2 & (p . 3) = p3 by A2, FINSEQ_1: 45;

      p = |[p1, p2, p3]| by A2;

      then

      reconsider ru = p as Element of ( REAL 3) by EUCLID: 22;

      

       A4: ( MXR2MXF ( ColVec2Mx p)) = ( <*ru*> @ ) by ANPROJ_8: 72;

      reconsider a, b, c, d, e, f, g, h, i as Element of F_Real ;

      reconsider fu1 = (ru . 1), fu2 = (ru . 2), fu3 = (ru . 3) as Element of F_Real by XREAL_0:def 1;

      

       A5: ( <*ru*> @ ) = <* <*fu1*>, <*fu2*>, <*fu3*>*> by EUCLID_8: 50, ANPROJ_8: 77;

      

       A6: ( len ru) = 3 by EUCLID_8: 50;

      

       A7: ( len <*ru*>) = 1 by FINSEQ_1: 39;

      ( rng <*ru*>) = {ru} by FINSEQ_1: 39;

      then ru in ( rng <*ru*>) by TARSKI:def 1;

      then

       A8: ( width <*ru*>) = 3 by A6, A7, MATRIX_0:def 3;

      

      then

       A9: ( width ( <*ru*> @ )) = ( len <*ru*>) by MATRIX_0: 29

      .= 1 by FINSEQ_1: 39;

      

       A10: ( len ( <*ru*> @ )) = 3 by MATRIX_0:def 6, A8;

      then

       A11: ( <*ru*> @ ) is Matrix of 3, 1, F_Real by A9, MATRIX_0: 20;

      reconsider M2 = ( <*ru*> @ ) as Matrix of 3, 1, F_Real by A10, A9, MATRIX_0: 20;

      

       A12: (M * ( ColVec2Mx p)) = (M * ( <*ru*> @ )) by A4, MATRIXR1:def 1

      .= ( MXF2MXR (( MXR2MXF M) * ( MXR2MXF ( <*ru*> @ )))) by MATRIXR1:def 6;

      

       A13: ( MXR2MXF ( <*ru*> @ )) is Matrix of 3, 1, F_Real by MATRIXR1:def 1, A11;

      

       A14: ( MXR2MXF ( <*ru*> @ )) = <* <*fu1*>, <*fu2*>, <*fu3*>*> by A5, MATRIXR1:def 1;

      

       A15: (( MXR2MXF M) * ( MXR2MXF ( <*ru*> @ ))) = <* <*(((a * fu1) + (b * fu2)) + (c * fu3))*>, <*(((d * fu1) + (e * fu2)) + (f * fu3))*>, <*(((g * fu1) + (h * fu2)) + (i * fu3))*>*> by A13, A1, MATRIXR1:def 1, A14, ANPROJ_9: 7;

      reconsider q = <*(((a * fu1) + (b * fu2)) + (c * fu3)), (((d * fu1) + (e * fu2)) + (f * fu3)), (((g * fu1) + (h * fu2)) + (i * fu3))*> as FinSequence of REAL ;

      

       A16: (q . 1) = (((a * fu1) + (b * fu2)) + (c * fu3)) & (q . 2) = (((d * fu1) + (e * fu2)) + (f * fu3)) & (q . 3) = (((g * fu1) + (h * fu2)) + (i * fu3)) by FINSEQ_1: 45;

      q = |[(((a * fu1) + (b * fu2)) + (c * fu3)), (((d * fu1) + (e * fu2)) + (f * fu3)), (((g * fu1) + (h * fu2)) + (i * fu3))]|;

      then

      reconsider rq = q as Element of ( REAL 3) by EUCLID: 22;

      reconsider qf = q as FinSequence of F_Real ;

      

       A17: ( len q) = 3 by FINSEQ_1: 45;

      

       A18: ( ColVec2Mx rq) = ( MXR2MXF ( ColVec2Mx rq)) by MATRIXR1:def 1

      .= ( <*qf*> @ ) by ANPROJ_8: 72;

      

      then

       A19: ( ColVec2Mx rq) = ( F2M q) by A17, ANPROJ_8: 88

      .= <* <*(((a * fu1) + (b * fu2)) + (c * fu3))*>, <*(((d * fu1) + (e * fu2)) + (f * fu3))*>, <*(((g * fu1) + (h * fu2)) + (i * fu3))*>*> by A16, A17, ANPROJ_8:def 1

      .= (M * ( ColVec2Mx p)) by A15, A12, MATRIXR1:def 2;

      (M * p) = ( Col (( ColVec2Mx rq),1)) by A19, MATRIXR1:def 11

      .= <*(((a * fu1) + (b * fu2)) + (c * fu3)), (((d * fu1) + (e * fu2)) + (f * fu3)), (((g * fu1) + (h * fu2)) + (i * fu3))*> by A18, ANPROJ_8: 93;

      hence thesis by A3;

    end;

    

     Lm16: for M be Matrix of 3, REAL st p = ( 0. ( TOP-REAL 3)) holds (M * p) = p

    proof

      let M be Matrix of 3, REAL ;

      assume

       A1: p = ( 0. ( TOP-REAL 3));

      consider a,b,c,d,e,f,g,h,i be Element of REAL such that

       A2: ( MXR2MXF M) = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> by Th03;

      

       A3: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> by A2, MATRIXR1:def 1;

      set u = ( 0. ( TOP-REAL 3));

      

       A4: (p . 1) = 0 & (p . 2) = 0 & (p . 3) = 0 by A1, EUCLID_5: 4, FINSEQ_1: 45;

      reconsider r1 = (p . 1), r2 = (p . 2), r3 = (p . 3) as Element of REAL by XREAL_0:def 1;

      

       A5: p = <*r1, r2, r3*> by A1, EUCLID_5: 4, A4;

      (M * p) = <*(((a * r1) + (b * r2)) + (c * r3)), (((d * r1) + (e * r2)) + (f * r3)), (((g * r1) + (h * r2)) + (i * r3))*> by A3, A5, Th09

      .= <* 0 , 0 , 0 *> by A4;

      hence thesis by A1, EUCLID_5: 4;

    end;

    

     Lm17: <* <* 0 , 0 , 0 *>, <* 0 , 0 , 0 *>, <* 0 , 0 , 0 *>*> = ( 0. ( F_Real ,3,3))

    proof

      

       A1: ( 0. ( F_Real ,3,3)) = (3 |-> (3 |-> ( 0. F_Real ))) by MATRIX_3:def 1;

      (3 |-> ( 0. F_Real )) = <* 0 , 0 , 0 *> by FINSEQ_2: 62;

      hence thesis by A1, FINSEQ_2: 62;

    end;

    

     Lm18: <* <* 0 , 0 , 0 *>, <* 0 , 0 , 0 *>, <* 0 , 0 , 0 *>*> = ( 0_Rmatrix 3)

    proof

      ( 0_Rmatrix 3) = ( MXF2MXR ( 0. ( F_Real ,3,3))) by MATRIXR1:def 8;

      hence thesis by MATRIXR1:def 2, Lm17;

    end;

    

     Lm19: for M be Matrix of n, K st n > 0 holds (M * ( 0. (K,n,n))) = ( 0. (K,n,n))

    proof

      let M be Matrix of n, K;

      assume

       A1: n > 0 ;

      

       A2: ( len ( 0. (K,n,n))) = ( len ( 0. (K,n,n))) & ( width ( 0. (K,n,n))) = ( width ( 0. (K,n,n)));

      

       A3: ( len M) = n & ( width M) = n & ( len ( 0. (K,n,n))) = n by MATRIX_0: 24;

      reconsider M0 = (M * ( 0. (K,n,n))) as Matrix of K;

      

       A4: ( len M0) = n & ( width M0) = n by MATRIX_0: 24;

      (M * ( 0. (K,n,n))) = (M * (( 0. (K,n,n)) + ( 0. (K,n,n)))) by MATRIX_3: 4

      .= ((M * ( 0. (K,n,n))) + (M * ( 0. (K,n,n)))) by A2, A3, A1, MATRIX_4: 62;

      hence thesis by A4, MATRIX_4: 6;

    end;

    

     Lm20: for M be Matrix of 3, REAL holds (M * ( 0_Rmatrix 3)) = ( 0_Rmatrix 3) & (( 0_Rmatrix 3) * M) = ( 0_Rmatrix 3)

    proof

      let M be Matrix of 3, REAL ;

      

       A1: ( width ( MXR2MXF M)) = 3 & ( len ( MXR2MXF M)) = 3 by MATRIX_0: 24;

      ( 0. ( F_Real ,3,3)) = (( MXR2MXF M) * ( 0. ( F_Real ,3,3))) by Lm19;

      

      hence ( 0_Rmatrix 3) = ( MXF2MXR (( MXR2MXF M) * ( 0. ( F_Real ,3,3)))) by MATRIXR1:def 8

      .= (( MXF2MXR ( MXR2MXF M)) * ( MXF2MXR ( 0. ( F_Real ,3,3)))) by Lm05

      .= (M * ( MXF2MXR ( 0. ( F_Real ,3,3)))) by Lm06

      .= (M * ( 0_Rmatrix 3)) by MATRIXR1:def 8;

      ( 0. ( F_Real ,3,3)) = (( 0. ( F_Real ,3,3)) * ( MXR2MXF M)) by A1, MATRIX_5: 22;

      

      hence ( 0_Rmatrix 3) = ( MXF2MXR (( 0. ( F_Real ,3,3)) * ( MXR2MXF M))) by MATRIXR1:def 8

      .= (( MXF2MXR ( 0. ( F_Real ,3,3))) * ( MXF2MXR ( MXR2MXF M))) by Lm05

      .= (( MXF2MXR ( 0. ( F_Real ,3,3))) * M) by Lm06

      .= (( 0_Rmatrix 3) * M) by MATRIXR1:def 8;

    end;

    begin

    definition

      let a,b,c,d,e,f be Real;

      let u be Element of ( TOP-REAL 3);

      :: PASCAL:def1

      func qfconic (a,b,c,d,e,f,u) -> Real equals (((((((a * (u . 1)) * (u . 1)) + ((b * (u . 2)) * (u . 2))) + ((c * (u . 3)) * (u . 3))) + ((d * (u . 1)) * (u . 2))) + ((e * (u . 1)) * (u . 3))) + ((f * (u . 2)) * (u . 3)));

      coherence ;

    end

    definition

      let a,b,c,d,e,f be Real;

      :: PASCAL:def2

      func conic (a,b,c,d,e,f) -> Subset of ( ProjectiveSpace ( TOP-REAL 3)) equals { P where P be Point of ( ProjectiveSpace ( TOP-REAL 3)) : for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a,b,c,d,e,f,u)) = 0 };

      coherence

      proof

        set C = { P where P be Point of ( ProjectiveSpace ( TOP-REAL 3)) : for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a,b,c,d,e,f,u)) = 0 };

        C c= the carrier of ( ProjectiveSpace ( TOP-REAL 3))

        proof

          let x be object;

          assume x in C;

          then ex P be Point of ( ProjectiveSpace ( TOP-REAL 3)) st x = P & for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a,b,c,d,e,f,u)) = 0 ;

          hence thesis;

        end;

        hence thesis;

      end;

    end

    reserve a,b,c,d,e,f for Real;

    reserve u,u1,u2 for non zero Element of ( TOP-REAL 3);

    reserve P for Element of ( ProjectiveSpace ( TOP-REAL 3));

    theorem :: PASCAL:10

    

     Th10: ( Dir u1) = ( Dir u2) & ( qfconic (a,b,c,d,e,f,u1)) = 0 implies ( qfconic (a,b,c,d,e,f,u2)) = 0

    proof

      assume that

       A1: ( Dir u1) = ( Dir u2) and

       A2: ( qfconic (a,b,c,d,e,f,u1)) = 0 ;

       are_Prop (u1,u2) by A1, ANPROJ_1: 22;

      then

      consider r be Real such that

       A3: r <> 0 and

       A4: u1 = (r * u2) by ANPROJ_1: 1;

      r is non zero by A3;

      then

       A5: (r * r) <> 0 by ORDINAL1:def 14;

      (u1 . 1) = (r * (u2 . 1)) & (u1 . 2) = (r * (u2 . 2)) & (u1 . 3) = (r * (u2 . 3)) by A4, RVSUM_1: 44;

      then ((r * r) * (((((((a * (u2 . 1)) * (u2 . 1)) + ((b * (u2 . 2)) * (u2 . 2))) + ((c * (u2 . 3)) * (u2 . 3))) + ((d * (u2 . 1)) * (u2 . 2))) + ((e * (u2 . 1)) * (u2 . 3))) + ((f * (u2 . 3)) * (u2 . 2)))) = ((r * r) * 0 ) by A2;

      hence thesis by A5, XCMPLX_1: 5;

    end;

    theorem :: PASCAL:11

    

     Th11: P = ( Dir u) & ( qfconic (a,b,c,d,e,f,u)) = 0 implies P in ( conic (a,b,c,d,e,f))

    proof

      assume that

       A2: P = ( Dir u) and

       A3: ( qfconic (a,b,c,d,e,f,u)) = 0 ;

      for v be Element of ( TOP-REAL 3) st v is non zero & P = ( Dir v) holds ( qfconic (a,b,c,d,e,f,v)) = 0 by A2, A3, Th10;

      hence thesis;

    end;

    definition

      let a,b,c,d,e,f be Real;

      :: PASCAL:def3

      func symmetric_3 (a,b,c,d,e,f) -> Matrix of 3, F_Real equals <* <*a, d, e*>, <*d, b, f*>, <*e, f, c*>*>;

      coherence

      proof

        reconsider fr1 = a, fr2 = b, fr3 = c, fr4 = d, fr5 = e, fr6 = f as Element of F_Real by XREAL_0:def 1;

        set S = <* <*fr1, fr4, fr5*>, <*fr4, fr2, fr6*>, <*fr5, fr6, fr3*>*>;

        S is Matrix of 3, F_Real by MATRIXR2: 35;

        hence thesis;

      end;

    end

    theorem :: PASCAL:12

    

     Th12: ( symmetric_3 (a,b,c,d,e,f)) is symmetric

    proof

      reconsider a, b, c, d, e, f as Element of F_Real by XREAL_0:def 1;

      (( symmetric_3 (a,b,c,d,e,f)) @ ) = <* <*a, d, e*>, <*d, b, f*>, <*e, f, c*>*> by Th05;

      hence thesis by MATRIX_6:def 5;

    end;

    theorem :: PASCAL:13

    

     Th13: for a,b,c,d,e,f be Real, u be Point of ( TOP-REAL 3), M be Matrix of 3, REAL st p = u & M = ( symmetric_3 (a,b,c,d,e,f)) holds ( SumAll ( QuadraticForm (p,M,p))) = ( qfconic (a,b,c,(2 * d),(2 * e),(2 * f),u))

    proof

      let a,b,c,d,e,f be Real;

      let u be Point of ( TOP-REAL 3);

      let M be Matrix of 3, REAL ;

      assume that

       A1: p = u and

       A2: M = ( symmetric_3 (a,b,c,d,e,f));

      reconsider ru = u as Element of ( REAL 3) by EUCLID: 22;

      

       A3: ( MXR2MXF ( ColVec2Mx p)) = ( <*ru*> @ ) by A1, ANPROJ_8: 72;

      reconsider a, b, c, d, e, f as Element of F_Real by XREAL_0:def 1;

      reconsider fu1 = (ru . 1), fu2 = (ru . 2), fu3 = (ru . 3) as Element of F_Real by XREAL_0:def 1;

      

       A4: ( <*ru*> @ ) = <* <*fu1*>, <*fu2*>, <*fu3*>*> by EUCLID_8: 50, ANPROJ_8: 77;

      

       A5: ( len ru) = 3 by EUCLID_8: 50;

      

       A6: ( len <*ru*>) = 1 by FINSEQ_1: 39;

      ( rng <*ru*>) = {ru} by FINSEQ_1: 39;

      then ru in ( rng <*ru*>) by TARSKI:def 1;

      then

       A7: ( width <*ru*>) = 3 by A5, A6, MATRIX_0:def 3;

      

      then

       A8: ( width ( <*ru*> @ )) = ( len <*ru*>) by MATRIX_0: 29

      .= 1 by FINSEQ_1: 39;

      

       A9: ( len ( <*ru*> @ )) = 3 by MATRIX_0:def 6, A7;

      then

       A10: ( <*ru*> @ ) is Matrix of 3, 1, F_Real by A8, MATRIX_0: 20;

      reconsider M2 = ( <*ru*> @ ) as Matrix of 3, 1, F_Real by A9, A8, MATRIX_0: 20;

      

       A11: (M * ( ColVec2Mx p)) = (M * ( <*ru*> @ )) by A3, MATRIXR1:def 1

      .= ( MXF2MXR (( MXR2MXF M) * ( MXR2MXF ( <*ru*> @ )))) by MATRIXR1:def 6;

      

       A12: ( MXR2MXF ( <*ru*> @ )) is Matrix of 3, 1, F_Real by MATRIXR1:def 1, A10;

      

       A13: ( MXR2MXF ( <*ru*> @ )) = <* <*fu1*>, <*fu2*>, <*fu3*>*> by A4, MATRIXR1:def 1;

      

       A14: (( MXR2MXF M) * ( MXR2MXF ( <*ru*> @ ))) = <* <*(((a * fu1) + (d * fu2)) + (e * fu3))*>, <*(((d * fu1) + (b * fu2)) + (f * fu3))*>, <*(((e * fu1) + (f * fu2)) + (c * fu3))*>*> by A12, A2, MATRIXR1:def 1, A13, ANPROJ_9: 7;

      reconsider q = <*(((a * fu1) + (d * fu2)) + (e * fu3)), (((d * fu1) + (b * fu2)) + (f * fu3)), (((e * fu1) + (f * fu2)) + (c * fu3))*> as FinSequence of REAL ;

      

       A15: (q . 1) = (((a * fu1) + (d * fu2)) + (e * fu3)) & (q . 2) = (((d * fu1) + (b * fu2)) + (f * fu3)) & (q . 3) = (((e * fu1) + (f * fu2)) + (c * fu3)) by FINSEQ_1: 45;

      

       A16: |[(((a * (u . 1)) + (d * (u . 2))) + (e * (u . 3))), (((d * (u . 1)) + (b * (u . 2))) + (f * (u . 3))), (((e * (u . 1)) + (f * (u . 2))) + (c * (u . 3)))]| in ( TOP-REAL 3);

      then

      reconsider rq = q as Element of ( REAL 3) by EUCLID: 22;

      reconsider qf = q as FinSequence of F_Real ;

      

       A17: ( len q) = 3 by FINSEQ_1: 45;

      

       A18: ( ColVec2Mx rq) = ( MXR2MXF ( ColVec2Mx rq)) by MATRIXR1:def 1

      .= ( <*qf*> @ ) by ANPROJ_8: 72;

      

      then

       A19: ( ColVec2Mx rq) = ( F2M q) by A17, ANPROJ_8: 88

      .= <* <*(((a * fu1) + (d * fu2)) + (e * fu3))*>, <*(((d * fu1) + (b * fu2)) + (f * fu3))*>, <*(((e * fu1) + (f * fu2)) + (c * fu3))*>*> by A15, A17, ANPROJ_8:def 1

      .= (M * ( ColVec2Mx p)) by A14, A11, MATRIXR1:def 2;

      

       A20: (M * p) = ( Col (( ColVec2Mx rq),1)) by A19, MATRIXR1:def 11

      .= <*(((a * fu1) + (d * fu2)) + (e * fu3)), (((d * fu1) + (b * fu2)) + (f * fu3)), (((e * fu1) + (f * fu2)) + (c * fu3))*> by A18, ANPROJ_8: 93;

      then

       A21: ((M * p) . 1) = (((a * fu1) + (d * fu2)) + (e * fu3)) & ((M * p) . 2) = (((d * fu1) + (b * fu2)) + (f * fu3)) & ((M * p) . 3) = (((e * fu1) + (f * fu2)) + (c * fu3)) by FINSEQ_1: 45;

      

       A22: ( len M) = 3 & ( width M) = 3 by MATRIX_0: 24;

      u in ( TOP-REAL 3);

      then u in ( REAL 3) by EUCLID: 22;

      then

       A23: ( len p) = 3 by A1, EUCLID_8: 50;

      reconsider Mp = (M * p) as Element of ( REAL 3) by A16, A20, EUCLID: 22;

       |(p, (M * p))| = ((((ru . 1) * (Mp . 1)) + ((ru . 2) * (Mp . 2))) + ((ru . 3) * (Mp . 3))) by A1, EUCLID_8: 63

      .= ( qfconic (a,b,c,(2 * d),(2 * e),(2 * f),u)) by A21;

      hence thesis by A23, A22, MATRPROB: 44;

    end;

    theorem :: PASCAL:14

    

     Th14: for N be invertible Matrix of 3, F_Real holds for NR,M1,M2 be Matrix of 3, REAL holds for a,b,c,d,e,f be Real st NR = ( MXF2MXR N) & M1 = ( symmetric_3 (a,b,c,(d / 2),(f / 2),(e / 2))) & M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M1) * ( MXF2MXR (( MXR2MXF NR) ~ ))) holds ( MXR2MXF M2) is symmetric

    proof

      let N be invertible Matrix of 3, F_Real ;

      let NR,M1,M2 be Matrix of 3, REAL ;

      let a,b,c,d,e,f be Real;

      assume

       A1: NR = ( MXF2MXR N) & M1 = ( symmetric_3 (a,b,c,(d / 2),(f / 2),(e / 2))) & M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M1) * ( MXF2MXR (( MXR2MXF NR) ~ )));

      reconsider M = ( symmetric_3 (a,b,c,(d / 2),(f / 2),(e / 2))) as Matrix of 3, REAL ;

      

       A2: ( MXR2MXF M) = ( symmetric_3 (a,b,c,(d / 2),(f / 2),(e / 2))) by MATRIXR1:def 1;

      reconsider Q = (( MXR2MXF (NR @ )) ~ ) as Matrix of 3, F_Real ;

      reconsider T = ( MXF2MXR (( MXR2MXF (NR @ )) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

      (T * M) is Matrix of 3, REAL ;

      then

      reconsider M3 = (( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M), M4 = ( MXF2MXR (( MXR2MXF NR) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

      reconsider M5 = (( MXR2MXF (NR @ )) ~ ) as Matrix of 3, F_Real ;

      reconsider M6 = ( MXF2MXR M5) as Matrix of 3, REAL by MATRIXR1:def 2;

      (NR @ ) is invertible by A1, Lm12;

      then

       A3: ( MXR2MXF (NR @ )) is invertible by Lm15;

      

       A4: (( MXR2MXF (NR @ )) @ ) = ( MXR2MXF NR)

      proof

        reconsider N1 = ( MXF2MXR N) as Matrix of 3, REAL by MATRIXR1:def 2;

        

         A5: (NR @ ) = (N @ ) by A1, MATRIXR1:def 2;

        reconsider N2 = ( MXR2MXF (NR @ )) as Matrix of 3, F_Real ;

        

         A6: ( len N) = 3 & ( width N) = 3 by MATRIX_0: 24;

        (( MXR2MXF (NR @ )) @ ) = ((N @ ) @ ) by A5, MATRIXR1:def 1

        .= N by A6, MATRIX_0: 57;

        hence thesis by A1, ANPROJ_8: 16;

      end;

      

       A7: (M5 @ ) = (( MXR2MXF NR) ~ ) by A3, MATRIX14: 31, A4;

      ( MXR2MXF M2) is symmetric

      proof

        

         A8: ( len M5) = 3 & ( width M5) = 3 by MATRIX_0: 24;

        ( MXR2MXF M2) = (( MXR2MXF M3) * ( MXR2MXF M4)) by A1, Lm07

        .= (( MXR2MXF (M6 * M)) * ( MXR2MXF ( MXF2MXR (( MXR2MXF NR) ~ ))))

        .= ((( MXR2MXF ( MXF2MXR M5)) * ( MXR2MXF M)) * ( MXR2MXF ( MXF2MXR (( MXR2MXF NR) ~ )))) by Lm07

        .= ((M5 * ( MXR2MXF M)) * ( MXR2MXF ( MXF2MXR (( MXR2MXF NR) ~ )))) by ANPROJ_8: 16

        .= ((M5 * ( MXR2MXF M)) * (( MXR2MXF NR) ~ )) by ANPROJ_8: 16

        .= ((((M5 @ ) @ ) * ( MXR2MXF M)) * (M5 @ )) by A7, A8, MATRIX_0: 57;

        hence thesis by A2, Th12, Th07;

      end;

      hence thesis;

    end;

    theorem :: PASCAL:15

    

     Th15: for a1,a2,a3,a4,a5,a6,b1,b2,b3,b4,b5,b6 be Real st ( symmetric_3 (a1,a2,a3,a4,a5,a6)) = ( symmetric_3 (b1,b2,b3,b4,b5,b6)) holds a1 = b1 & a2 = b2 & a3 = b3 & a4 = b4 & a5 = b5 & a6 = b6

    proof

      let a1,a2,a3,a4,a5,a6,b1,b2,b3,b4,b5,b6 be Real;

      assume

       A1: ( symmetric_3 (a1,a2,a3,a4,a5,a6)) = ( symmetric_3 (b1,b2,b3,b4,b5,b6));

      reconsider fa1 = a1, fa2 = a2, fa3 = a3, fa4 = a4, fa5 = a5, fa6 = a6, fb1 = b1, fb2 = b2, fb3 = b3, fb4 = b4, fb5 = b5, fb6 = b6 as Element of F_Real by XREAL_0:def 1;

       <* <*fa1, fa4, fa5*>, <*fa4, fa2, fa6*>, <*fa5, fa6, fa3*>*> = <* <*fb1, fb4, fb5*>, <*fb4, fb2, fb6*>, <*fb5, fb6, fb3*>*> by A1;

      hence thesis by Th02;

    end;

    theorem :: PASCAL:16

    

     Th16: for a,b,c,d,e,f be Real holds for P be Point of ( ProjectiveSpace ( TOP-REAL 3)) holds for N be invertible Matrix of 3, F_Real st not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) & P in ( conic (a,b,c,d,e,f)) holds (for fa,fb,fc,fd,fe,fi,ff be Real holds for M1,M2 be Matrix of 3, REAL holds for NR be Matrix of 3, REAL st M1 = ( symmetric_3 (a,b,c,(d / 2),(e / 2),(f / 2))) & NR = ( MXF2MXR N) & M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M1) * ( MXF2MXR (( MXR2MXF NR) ~ ))) & M2 = ( symmetric_3 (fa,fe,fi,fb,fc,ff)) holds not (fa = 0 & fe = 0 & fi = 0 & fb = 0 & ff = 0 & fc = 0 ) & (( homography N) . P) in ( conic (fa,fe,fi,(2 * fb),(2 * fc),(2 * ff))))

    proof

      let a,b,c,d,e,f be Real;

      let P be Point of ( ProjectiveSpace ( TOP-REAL 3));

      let N be invertible Matrix of 3, F_Real ;

      assume that

       A1: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) and

       A2: P in ( conic (a,b,c,d,e,f));

      consider Q be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

       A3: P = Q and

       A4: for u be Element of ( TOP-REAL 3) st u is non zero & Q = ( Dir u) holds ( qfconic (a,b,c,d,e,f,u)) = 0 by A2;

      reconsider M = ( symmetric_3 (a,b,c,(d / 2),(e / 2),(f / 2))) as Matrix of 3, REAL ;

      

       A5: ( MXR2MXF M) = ( symmetric_3 (a,b,c,(d / 2),(e / 2),(f / 2))) by MATRIXR1:def 1;

      consider uh,vh be Element of ( TOP-REAL 3), ufh be FinSequence of F_Real , ph be FinSequence of (1 -tuples_on REAL ) such that

       A6: P = ( Dir uh) & not uh is zero & uh = ufh & ph = (N * ufh) & vh = ( M2F ph) & not vh is zero & (( homography N) . P) = ( Dir vh) by ANPROJ_8:def 4;

      reconsider pR = uh as FinSequence of REAL by EUCLID: 24;

      

       A7: ( SumAll ( QuadraticForm (pR,M,pR))) = ( qfconic (a,b,c,(2 * (d / 2)),(2 * (e / 2)),(2 * (f / 2)),uh)) by Th13

      .= 0 by A3, A4, A6;

      reconsider x = (uh `1 ), y = (uh `2 ), z = (uh `3 ) as Element of F_Real by XREAL_0:def 1;

      

       A8: ufh = <*x, y, z*> by A6, EUCLID_5: 27;

      consider an,bn,cn,dn,en,fn,gn,hn,iN be Element of F_Real such that

       A9: N = <* <*an, bn, cn*>, <*dn, en, fn*>, <*gn, hn, iN*>*> by Th03;

      reconsider uf = ufh as FinSequence of REAL ;

      reconsider NR = ( MXF2MXR N) as Matrix of 3, REAL by MATRIXR1:def 2;

      reconsider M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M) * ( MXF2MXR (( MXR2MXF NR) ~ ))) as Matrix of 3, REAL by Lm03;

      reconsider T = ( MXF2MXR (( MXR2MXF (NR @ )) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

      (T * M) is Matrix of 3, REAL ;

      then

      reconsider M3 = (( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M), M4 = ( MXF2MXR (( MXR2MXF NR) ~ )) as Matrix of 3, REAL by MATRIXR1:def 2;

      reconsider M5 = (( MXR2MXF (NR @ )) ~ ) as Matrix of 3, F_Real ;

      reconsider M6 = ( MXF2MXR M5) as Matrix of 3, REAL by MATRIXR1:def 2;

      (NR @ ) is invertible by Lm12;

      then

       A10: ( MXR2MXF (NR @ )) is invertible by Lm15;

      (( MXR2MXF (NR @ )) @ ) = ( MXR2MXF NR)

      proof

        reconsider N1 = ( MXF2MXR N) as Matrix of 3, REAL by MATRIXR1:def 2;

        

         A11: (NR @ ) = (N @ ) by MATRIXR1:def 2;

        reconsider N2 = ( MXR2MXF (NR @ )) as Matrix of 3, F_Real ;

        

         A12: ( len N) = 3 & ( width N) = 3 by MATRIX_0: 24;

        (( MXR2MXF (NR @ )) @ ) = ((N @ ) @ ) by A11, MATRIXR1:def 1

        .= N by A12, MATRIX_0: 57;

        hence thesis by ANPROJ_8: 16;

      end;

      then

       A13: (M5 @ ) = (( MXR2MXF NR) ~ ) by A10, MATRIX14: 31;

      

       A14: ( MXR2MXF M2) is symmetric

      proof

        

         A15: ( len M5) = 3 & ( width M5) = 3 by MATRIX_0: 24;

        ( MXR2MXF M2) = (( MXR2MXF M3) * ( MXR2MXF M4)) by Lm07

        .= (( MXR2MXF (M6 * M)) * ( MXR2MXF ( MXF2MXR (( MXR2MXF NR) ~ ))))

        .= ((( MXR2MXF ( MXF2MXR M5)) * ( MXR2MXF M)) * ( MXR2MXF ( MXF2MXR (( MXR2MXF NR) ~ )))) by Lm07

        .= ((M5 * ( MXR2MXF M)) * ( MXR2MXF ( MXF2MXR (( MXR2MXF NR) ~ )))) by ANPROJ_8: 16

        .= ((M5 * ( MXR2MXF M)) * (( MXR2MXF NR) ~ )) by ANPROJ_8: 16

        .= ((((M5 @ ) @ ) * ( MXR2MXF M)) * (M5 @ )) by A13, A15, MATRIX_0: 57;

        hence thesis by A5, Th12, Th07;

      end;

      consider ma,mb,mc,md,me,mf,mg,mh,mi be Element of F_Real such that

       A16: M2 = <* <*ma, mb, mc*>, <*md, me, mf*>, <*mg, mh, mi*>*> by Th03;

      ( MXR2MXF M2) = <* <*ma, mb, mc*>, <*md, me, mf*>, <*mg, mh, mi*>*> by A16, MATRIXR1:def 1;

      then

       A17: mb = md & mc = mg & mh = mf by A14, Th06;

      uh in ( TOP-REAL 3);

      then uh in ( REAL 3) by EUCLID: 22;

      then

       A18: ( len uf) = 3 by A6, EUCLID_8: 50;

      

       A19: ( len (((NR @ ) * M2) * NR)) = 3 & ( width (((NR @ ) * M2) * NR)) = 3 by MATRIX_0: 24;

      

       A20: |((NR * uf), (M2 * (NR * uf)))| = |(uf, ((((NR @ ) * M2) * NR) * uf))| by A18, Lm02

      .= ( SumAll ( QuadraticForm (uf,(((NR @ ) * M2) * NR),uf))) by A18, A19, MATRPROB: 44

      .= 0 by A6, A7, Lm13;

      ( width NR) = 3 by MATRIX_0: 24;

      then ( len (NR * uf)) = ( len NR) by A18, MATRIXR1: 61;

      then

       A21: ( len (NR * uf)) = 3 by MATRIX_0: 24;

      then ( len (NR * uf)) = ( len M2) & ( len (NR * uf)) = ( width M2) & ( len (NR * uf)) > 0 by MATRIX_0: 24;

      then

       A22: ( SumAll ( QuadraticForm ((NR * uf),M2,(NR * uf)))) = 0 by A20, MATRPROB: 44;

      reconsider u3 = (NR * uf) as Element of ( TOP-REAL 3) by A21, EUCLID: 76;

      u3 is non zero

      proof

        assume

         A23: u3 is zero;

        reconsider p = ( 0. ( TOP-REAL 3)) as FinSequence of REAL by EUCLID: 24;

        

         A24: ( width NR) = 3 & ( width ( Inv NR)) = 3 & ( len NR) = 3 by MATRIX_0: 24;

        

         A25: NR is invertible by Lm14;

        (( Inv NR) * p) = ((( Inv NR) * NR) * uf) by A23, A24, A18, MATRIXR2: 59

        .= (( 1_Rmatrix 3) * uf) by A25, MATRIXR2:def 6

        .= uf by A18, MATRIXR2: 86;

        hence contradiction by Lm16, A6;

      end;

      then

      reconsider u2 = (NR * uf) as non zero Element of ( TOP-REAL 3);

      reconsider fa = ma, fb = mb, fc = mc, fe = me, ff = mf, fi = mi as Real;

      M2 = ( symmetric_3 (fa,fe,fi,fb,fc,ff)) by A16, A17;

      then

       A26: ( qfconic (fa,fe,fi,(2 * fb),(2 * fc),(2 * ff),u2)) = 0 by A22, Th13;

      

       A27: not (fa = 0 & fe = 0 & fi = 0 & (2 * fb) = 0 & (2 * ff) = 0 & (2 * fc) = 0 )

      proof

        assume

         A28: fa = 0 & fe = 0 & fi = 0 & (2 * fb) = 0 & (2 * ff) = 0 & (2 * fc) = 0 ;

        

         A29: (((NR @ ) * ( 0_Rmatrix 3)) * NR) = (( 0_Rmatrix 3) * NR) by Lm20

        .= ( 0_Rmatrix 3) by Lm20;

        reconsider z1 = 0 , z2 = 0 , z3 = 0 , z4 = 0 , z5 = 0 , z6 = 0 , z7 = 0 , z8 = 0 , z9 = 0 , a1 = a, b1 = b, c1 = c, d1 = (d / 2), e1 = (f / 2), f1 = (e / 2) as Element of F_Real by XREAL_0:def 1;

         <* <*a1, d1, f1*>, <*d1, b1, e1*>, <*f1, e1, c1*>*> = <* <*z1, z2, z3*>, <*z4, z5, z6*>, <*z7, z8, z9*>*> by A29, Lm13, A28, A17, A16, Lm18;

        then a1 = z1 & b1 = z5 & c1 = z9 & d1 = z2 & e1 = z5 & f1 = z3 by Th02;

        hence contradiction by A1;

      end;

      

       A30: u2 = vh

      proof

        ph = <* <*(((an * x) + (bn * y)) + (cn * z))*>, <*(((dn * x) + (en * y)) + (fn * z))*>, <*(((gn * x) + (hn * y)) + (iN * z))*>*> & vh = <*(((an * x) + (bn * y)) + (cn * z)), (((dn * x) + (en * y)) + (fn * z)), (((gn * x) + (hn * y)) + (iN * z))*> by A6, A8, A9, Th08;

        hence thesis by A8, Th09, A9, MATRIXR1:def 2;

      end;

      for ufa,ufb,ufc,ufd,ufe,ufi,uff be Real holds for UM1,UM2 be Matrix of 3, REAL holds for UNR be Matrix of 3, REAL st UM1 = ( symmetric_3 (a,b,c,(d / 2),(e / 2),(f / 2))) & UNR = ( MXF2MXR N) & UM2 = ((( MXF2MXR (( MXR2MXF (UNR @ )) ~ )) * UM1) * ( MXF2MXR (( MXR2MXF UNR) ~ ))) & UM2 = ( symmetric_3 (ufa,ufe,ufi,ufb,ufc,uff)) holds not (ufa = 0 & ufe = 0 & ufi = 0 & ufb = 0 & uff = 0 & ufc = 0 ) & (( homography N) . P) in ( conic (ufa,ufe,ufi,(2 * ufb),(2 * ufc),(2 * uff)))

      proof

        let ufa,ufb,ufc,ufd,ufe,ufi,uff be Real;

        let UM1,UM2 be Matrix of 3, REAL ;

        let UNR be Matrix of 3, REAL ;

        assume that

         A31: UM1 = ( symmetric_3 (a,b,c,(d / 2),(e / 2),(f / 2))) and

         A32: UNR = ( MXF2MXR N) and

         A33: UM2 = ((( MXF2MXR (( MXR2MXF (UNR @ )) ~ )) * UM1) * ( MXF2MXR (( MXR2MXF UNR) ~ ))) and

         A34: UM2 = ( symmetric_3 (ufa,ufe,ufi,ufb,ufc,uff));

        ( symmetric_3 (ufa,ufe,ufi,ufb,ufc,uff)) = ( symmetric_3 (fa,fe,fi,fb,fc,ff)) by A31, A32, A33, A34, A16, A17;

        then fa = ufa & fb = ufb & fc = ufc & fe = ufe & ff = uff & fi = ufi by Th15;

        hence not (ufa = 0 & ufe = 0 & ufi = 0 & ufb = 0 & uff = 0 & ufc = 0 ) & (( homography N) . P) in ( conic (ufa,ufe,ufi,(2 * ufb),(2 * ufc),(2 * uff))) by A27, A30, A26, A6, Th11;

      end;

      hence thesis;

    end;

    theorem :: PASCAL:17

    

     Th17: for a,b,c,d,e,f be Real holds for P1,P2,P3,P4,P5,P6 be Point of ( ProjectiveSpace ( TOP-REAL 3)) holds for N be invertible Matrix of 3, F_Real st not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) & P1 in ( conic (a,b,c,d,e,f)) & P2 in ( conic (a,b,c,d,e,f)) & P3 in ( conic (a,b,c,d,e,f)) & P4 in ( conic (a,b,c,d,e,f)) & P5 in ( conic (a,b,c,d,e,f)) & P6 in ( conic (a,b,c,d,e,f)) holds ex a2,b2,c2,d2,e2,f2 be Real st not (a2 = 0 & b2 = 0 & c2 = 0 & d2 = 0 & e2 = 0 & f2 = 0 ) & (( homography N) . P1) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P2) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P3) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P4) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P5) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P6) in ( conic (a2,b2,c2,d2,e2,f2))

    proof

      let a,b,c,d,e,f be Real;

      let P1,P2,P3,P4,P5,P6 be Point of ( ProjectiveSpace ( TOP-REAL 3));

      let N be invertible Matrix of 3, F_Real ;

      assume that

       A1: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) and

       A2: P1 in ( conic (a,b,c,d,e,f)) & P2 in ( conic (a,b,c,d,e,f)) & P3 in ( conic (a,b,c,d,e,f)) & P4 in ( conic (a,b,c,d,e,f)) & P5 in ( conic (a,b,c,d,e,f)) & P6 in ( conic (a,b,c,d,e,f));

      reconsider M1 = ( symmetric_3 (a,b,c,(d / 2),(e / 2),(f / 2))) as Matrix of 3, REAL ;

      reconsider NR = ( MXF2MXR N) as Matrix of 3, REAL by MATRIXR1:def 2;

      reconsider M2 = ((( MXF2MXR (( MXR2MXF (NR @ )) ~ )) * M1) * ( MXF2MXR (( MXR2MXF NR) ~ ))) as Matrix of 3, REAL by Lm03;

      consider ra,rb,rc,rd,re,rf,rg,rh,ri be Element of F_Real such that

       A3: ( MXR2MXF M2) = <* <*ra, rb, rc*>, <*rd, re, rf*>, <*rg, rh, ri*>*> by Th03;

      ( MXR2MXF M2) is symmetric by Th14;

      then

       A4: rb = rd & rc = rg & rf = rh by A3, Th06;

      reconsider fa = ra, fe = re, fi = ri, fb = rb, fc = rc, ff = rf as Real;

      

       A5: M2 = ( symmetric_3 (fa,fe,fi,fb,fc,ff)) by A3, A4, MATRIXR1:def 1;

      now

        reconsider a2 = ra, b2 = re, c2 = ri, d2 = (2 * rb), e2 = (2 * rc), f2 = (2 * rf) as Real;

        take a2, b2, c2, d2, e2, f2;

        thus not (a2 = 0 & b2 = 0 & c2 = 0 & d2 = 0 & e2 = 0 & f2 = 0 ) & (( homography N) . P1) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P2) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P3) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P4) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P5) in ( conic (a2,b2,c2,d2,e2,f2)) & (( homography N) . P6) in ( conic (a2,b2,c2,d2,e2,f2)) by A1, A2, A5, Th16;

      end;

      hence thesis;

    end;

    reserve a,b,c,d,e,f,g,h,i for Element of F_Real ;

    theorem :: PASCAL:18

    

     Th18: (( qfconic (a,b,c,d,e,f, |[1, 0 , 0 ]|)) = 0 implies a = 0 ) & (( qfconic (a,b,c,d,e,f, |[ 0 , 1, 0 ]|)) = 0 implies b = 0 ) & (( qfconic (a,b,c,d,e,f, |[ 0 , 0 , 1]|)) = 0 implies c = 0 ) & (( qfconic ( 0 , 0 , 0 ,d,e,f, |[1, 1, 1]|)) = 0 implies ((d + e) + f) = 0 )

    proof

      hereby

        assume

         A1: ( qfconic (a,b,c,d,e,f, |[1, 0 , 0 ]|)) = 0 ;

        ( |[1, 0 , 0 ]| . 1) = ( |[1, 0 , 0 ]| `1 ) & ( |[1, 0 , 0 ]| . 2) = ( |[1, 0 , 0 ]| `2 ) & ( |[1, 0 , 0 ]| . 3) = ( |[1, 0 , 0 ]| `3 ) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

        then ( |[1, 0 , 0 ]| . 1) = 1 & ( |[1, 0 , 0 ]| . 2) = 0 & ( |[1, 0 , 0 ]| . 3) = 0 by EUCLID_5: 2;

        hence a = 0 by A1;

      end;

      hereby

        assume

         A2: ( qfconic (a,b,c,d,e,f, |[ 0 , 1, 0 ]|)) = 0 ;

        ( |[ 0 , 1, 0 ]| . 1) = ( |[ 0 , 1, 0 ]| `1 ) & ( |[ 0 , 1, 0 ]| . 2) = ( |[ 0 , 1, 0 ]| `2 ) & ( |[ 0 , 1, 0 ]| . 3) = ( |[ 0 , 1, 0 ]| `3 ) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

        then ( |[ 0 , 1, 0 ]| . 1) = 0 & ( |[ 0 , 1, 0 ]| . 2) = 1 & ( |[ 0 , 1, 0 ]| . 3) = 0 by EUCLID_5: 2;

        hence b = 0 by A2;

      end;

      hereby

        assume

         A3: ( qfconic (a,b,c,d,e,f, |[ 0 , 0 , 1]|)) = 0 ;

        ( |[ 0 , 0 , 1]| . 1) = ( |[ 0 , 0 , 1]| `1 ) & ( |[ 0 , 0 , 1]| . 2) = ( |[ 0 , 0 , 1]| `2 ) & ( |[ 0 , 0 , 1]| . 3) = ( |[ 0 , 0 , 1]| `3 ) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

        then ( |[ 0 , 0 , 1]| . 1) = 0 & ( |[ 0 , 0 , 1]| . 2) = 0 & ( |[ 0 , 0 , 1]| . 3) = 1 by EUCLID_5: 2;

        hence c = 0 by A3;

      end;

      hereby

        assume

         A4: ( qfconic ( 0 , 0 , 0 ,d,e,f, |[1, 1, 1]|)) = 0 ;

        ( |[1, 1, 1]| . 1) = ( |[1, 1, 1]| `1 ) & ( |[1, 1, 1]| . 2) = ( |[1, 1, 1]| `2 ) & ( |[1, 1, 1]| . 3) = ( |[1, 1, 1]| `3 ) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

        then ( |[1, 1, 1]| . 1) = 1 & ( |[1, 1, 1]| . 2) = 1 & ( |[1, 1, 1]| . 3) = 1 by EUCLID_5: 2;

        hence ((d + e) + f) = 0 by A4;

      end;

    end;

    begin

    reserve M for Matrix of 3, F_Real ;

    reserve e1,e2,e3,f1,f2,f3 for Element of F_Real ;

    reserve MABC,MAEF,MDBF,MDEC,MDEF,MDBC,MAEC,MABF,MABE,MACF,MBDF,MCDE,MACE,MBDE,MCDF for Matrix of 3, F_Real ;

    reserve r1,r2 for Real;

    

     Lm21: a = 1 & b = 0 & c = 0 & d = 0 & e = 1 & f = 0 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = i

    proof

      assume that

       A1: a = 1 & b = 0 & c = 0 & d = 0 & e = 1 & f = 0 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= i by A1;

      hence thesis;

    end;

    

     Lm22: for d,e,f,g,h,i be Real st (r1 <> 0 or r2 <> 0 ) & (((r1 * d) * e) + ((r2 * d) * f)) = (((r1 + r2) * e) * f) & (((r1 * g) * h) + ((r2 * g) * i)) = (((r1 + r2) * h) * i) holds (((f * h) * (g - i)) * (d - e)) = (((i * e) * (d - f)) * (g - h))

    proof

      let d,e,f,g,h,i be Real;

      assume that

       A1: (r1 <> 0 or r2 <> 0 ) and

       A2: (((r1 * d) * e) + ((r2 * d) * f)) = (((r1 + r2) * e) * f) and

       A3: (((r1 * g) * h) + ((r2 * g) * i)) = (((r1 + r2) * h) * i);

      per cases by A1;

        suppose

         A4: r1 <> 0 ;

        

         A5: ((i * (h - g)) * (((e * (d - f)) * r1) + ((f * (d - e)) * r2))) = ((i * (h - g)) * 0 ) by A2;

        ((f * (e - d)) * (((h * (g - i)) * r1) + ((i * (g - h)) * r2))) = ((f * (e - d)) * 0 ) by A3;

        then ((((i * (g - h)) * e) * (d - f)) * r1) = ((((f * (d - e)) * h) * (g - i)) * r1) by A5;

        hence thesis by A4, XCMPLX_1: 5;

      end;

        suppose

         A6: r2 <> 0 ;

        ((h * (g - i)) * (((e * (d - f)) * r1) + ((f * (d - e)) * r2))) = ((h * (g - i)) * 0 ) by A2;

        then

         A7: ((((h * (g - i)) * e) * (d - f)) * r1) = ( - ((((h * (g - i)) * f) * (d - e)) * r2));

        ((e * (d - f)) * (((h * (g - i)) * r1) + ((i * (g - h)) * r2))) = ((e * (d - f)) * 0 ) by A3;

        then ((((e * (d - f)) * h) * (g - i)) * r1) = ( - ((((e * (d - f)) * i) * (g - h)) * r2));

        hence thesis by A7, A6, XCMPLX_1: 5;

      end;

    end;

    

     Lm23: a = 1 & b = 0 & c = 0 & d = 0 & e = 0 & f = 1 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = ( - h)

    proof

      assume that

       A1: a = 1 & b = 0 & c = 0 & d = 0 & e = 0 & f = 1 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= ( - h) by A1;

      hence thesis;

    end;

    

     Lm24: a = 0 & b = 1 & c = 0 & d = 1 & e = 1 & f = 1 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = (g - i)

    proof

      assume that

       A1: a = 0 & b = 1 & c = 0 & d = 1 & e = 1 & f = 1 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= (g - i) by A1;

      hence thesis;

    end;

    

     Lm25: a = 0 & b = 0 & c = 1 & d = 1 & e = 1 & f = 1 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = (h - g)

    proof

      assume that

       A1: a = 0 & b = 0 & c = 1 & d = 1 & e = 1 & f = 1 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= (h - g) by A1;

      hence thesis;

    end;

    

     Lm26: a = 1 & b = 0 & c = 0 & d = 0 & e = 1 & f = 0 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = i

    proof

      assume that

       A1: a = 1 & b = 0 & c = 0 & d = 0 & e = 1 & f = 0 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= i by A1;

      hence thesis;

    end;

    

     Lm27: a = 1 & b = 0 & c = 0 & d = 0 & e = 0 & f = 1 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = ( - h)

    proof

      assume that

       A1: a = 1 & b = 0 & c = 0 & d = 0 & e = 0 & f = 1 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= ( - h) by A1;

      hence thesis;

    end;

    

     Lm28: a = 0 & b = 1 & c = 0 & d = 1 & e = 1 & f = 1 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = (g - i)

    proof

      assume that

       A1: a = 0 & b = 1 & c = 0 & d = 1 & e = 1 & f = 1 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= (g - i) by A1;

      hence thesis;

    end;

    

     Lm29: a = 0 & b = 0 & c = 1 & d = 1 & e = 1 & f = 1 & M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*> implies ( Det M) = (h - g)

    proof

      assume that

       A1: a = 0 & b = 0 & c = 1 & d = 1 & e = 1 & f = 1 and

       A2: M = <* <*a, b, c*>, <*d, e, f*>, <*g, h, i*>*>;

      ( Det M) = (((((((a * e) * i) - ((c * e) * g)) - ((a * f) * h)) + ((b * f) * g)) - ((b * d) * i)) + ((c * d) * h)) by A2, MATRIX_9: 46

      .= (h - g) by A1;

      hence thesis;

    end;

    

     Lm30: MABE = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*e1, e2, e3*>*> & MACF = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*f1, f2, f3*>*> & MBDF = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*f1, f2, f3*>*> & MCDE = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*e1, e2, e3*>*> implies (((( Det MABE) * ( Det MACF)) * ( Det MBDF)) * ( Det MCDE)) = (((e3 * f2) * (f1 - f3)) * (e1 - e2))

    proof

      assume that

       A1: MABE = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*e1, e2, e3*>*> and

       A2: MACF = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*f1, f2, f3*>*> and

       A3: MBDF = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*f1, f2, f3*>*> and

       A4: MCDE = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*e1, e2, e3*>*>;

      ( Det MABE) = e3 & ( Det MACF) = ( - f2) & ( Det MBDF) = (f1 - f3) & ( Det MCDE) = (e2 - e1) by A1, A2, A3, A4, Lm21, Lm23, Lm24, Lm25;

      hence thesis;

    end;

    

     Lm31: MABF = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*f1, f2, f3*>*> & MACE = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*e1, e2, e3*>*> & MBDE = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*e1, e2, e3*>*> & MCDF = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*f1, f2, f3*>*> implies (((( Det MABF) * ( Det MACE)) * ( Det MBDE)) * ( Det MCDF)) = (((f3 * e2) * (e1 - e3)) * (f1 - f2))

    proof

      assume that

       A1: MABF = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*f1, f2, f3*>*> and

       A2: MACE = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*e1, e2, e3*>*> and

       A3: MBDE = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*e1, e2, e3*>*> and

       A4: MCDF = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*f1, f2, f3*>*>;

      ( Det MABF) = f3 & ( Det MACE) = ( - e2) & ( Det MBDE) = (e1 - e3) & ( Det MCDF) = (f2 - f1) by A1, A2, A3, A4, Lm26, Lm27, Lm28, Lm29;

      hence thesis;

    end;

    theorem :: PASCAL:19

    

     Th19: MABE = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*e1, e2, e3*>*> & MACF = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*f1, f2, f3*>*> & MBDF = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*f1, f2, f3*>*> & MCDE = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*e1, e2, e3*>*> & MABF = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*f1, f2, f3*>*> & MACE = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*e1, e2, e3*>*> & MBDE = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*e1, e2, e3*>*> & MCDF = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*f1, f2, f3*>*> & (r1 <> 0 or r2 <> 0 ) & ((((r1 * e1) * e2) + ((r2 * e1) * e3)) = (((r1 + r2) * e2) * e3) & (((r1 * f1) * f2) + ((r2 * f1) * f3)) = (((r1 + r2) * f2) * f3)) implies (((( Det MABE) * ( Det MACF)) * ( Det MBDF)) * ( Det MCDE)) = (((( Det MABF) * ( Det MACE)) * ( Det MBDE)) * ( Det MCDF))

    proof

      assume that

       A1: MABE = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*e1, e2, e3*>*> and

       A2: MACF = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*f1, f2, f3*>*> and

       A3: MBDF = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*f1, f2, f3*>*> and

       A4: MCDE = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*e1, e2, e3*>*> and

       A5: MABF = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*f1, f2, f3*>*> and

       A6: MACE = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*e1, e2, e3*>*> and

       A7: MBDE = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*e1, e2, e3*>*> and

       A8: MCDF = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*f1, f2, f3*>*> and

       A9: (r1 <> 0 or r2 <> 0 ) and

       A10: (((r1 * e1) * e2) + ((r2 * e1) * e3)) = (((r1 + r2) * e2) * e3) and

       A11: (((r1 * f1) * f2) + ((r2 * f1) * f3)) = (((r1 + r2) * f2) * f3);

      reconsider d = e1, e = e2, f = e3, g = f1, h = f2, i = f3 as Real;

      

       A12: (((( Det MABE) * ( Det MACF)) * ( Det MBDF)) * ( Det MCDE)) = (((e3 * f2) * (f1 - f3)) * (e1 - e2)) by A1, A2, A3, A4, Lm30;

      (((e3 * f2) * (f1 - f3)) * (e1 - e2)) = (((f3 * e2) * (e1 - e3)) * (f1 - f2)) by A9, A10, A11, Lm22;

      hence thesis by A12, A5, A6, A7, A8, Lm31;

    end;

    reserve p1,p2,p3,p4,p5,p6 for Point of ( TOP-REAL 3);

    theorem :: PASCAL:20

    

     Th20: MABE = <*p1, p2, p5*> & MACF = <*p1, p3, p6*> & MBDF = <*p2, p4, p6*> & MCDE = <*p3, p4, p5*> & MABF = <*p1, p2, p6*> & MACE = <*p1, p3, p5*> & MBDE = <*p2, p4, p5*> & MCDF = <*p3, p4, p6*> implies ( Det MABE) = |{p1, p2, p5}| & ( Det MACF) = |{p1, p3, p6}| & ( Det MBDF) = |{p2, p4, p6}| & ( Det MCDE) = |{p3, p4, p5}| & ( Det MABF) = |{p1, p2, p6}| & ( Det MACE) = |{p1, p3, p5}| & ( Det MBDE) = |{p2, p4, p5}| & ( Det MCDF) = |{p3, p4, p6}|

    proof

      assume that

       A1: MABE = <*p1, p2, p5*> and

       A2: MACF = <*p1, p3, p6*> and

       A3: MBDF = <*p2, p4, p6*> and

       A4: MCDE = <*p3, p4, p5*> and

       A5: MABF = <*p1, p2, p6*> and

       A6: MACE = <*p1, p3, p5*> and

       A7: MBDE = <*p2, p4, p5*> and

       A8: MCDF = <*p3, p4, p6*>;

      p1 = <*(p1 `1 ), (p1 `2 ), (p1 `3 )*> & p2 = <*(p2 `1 ), (p2 `2 ), (p2 `3 )*> & p3 = <*(p3 `1 ), (p3 `2 ), (p3 `3 )*> & p4 = <*(p4 `1 ), (p4 `2 ), (p4 `3 )*> & p5 = <*(p5 `1 ), (p5 `2 ), (p5 `3 )*> & p6 = <*(p6 `1 ), (p6 `2 ), (p6 `3 )*> by EUCLID_5: 3;

      hence thesis by A1, A2, A3, A4, A5, A6, A7, A8, ANPROJ_8: 35;

    end;

    reserve p7,p8,p9 for Point of ( TOP-REAL 3);

    theorem :: PASCAL:21

    

     Th21: |{p1, p5, p9}| = 0 implies ( |{p1, p5, p7}| * |{p2, p5, p9}|) = ( - ( |{p1, p2, p5}| * |{p5, p9, p7}|))

    proof

      assume

       A1: |{p1, p5, p9}| = 0 ;

      

       A2: |{p1, p2, p5}| = |{p5, p1, p2}| & |{p1, p5, p9}| = ( - |{p5, p1, p9}|) & |{p5, p1, p7}| = ( - |{p1, p5, p7}|) & |{p5, p2, p9}| = ( - |{p2, p5, p9}|) & |{p5, p9, p7}| = ( - |{p5, p7, p9}|) by ANPROJ_8: 29, ANPROJ_8: 30, Th01;

      then

       A3: |{p5, p1, p9}| = 0 by A1;

      ((( |{p5, p1, p7}| * |{p5, p2, p9}|) - ( |{p5, p1, p2}| * |{p5, p7, p9}|)) + ( |{p5, p1, p9}| * |{p5, p7, p2}|)) = 0 by ANPROJ_8: 28;

      hence thesis by A2, A3;

    end;

    theorem :: PASCAL:22

    

     Th22: |{p1, p6, p8}| = 0 implies ( |{p1, p2, p6}| * |{p3, p6, p8}|) = ( |{p1, p3, p6}| * |{p2, p6, p8}|)

    proof

      assume

       A1: |{p1, p6, p8}| = 0 ;

      

       A2: |{p1, p6, p8}| = ( - |{p6, p1, p8}|) & |{p6, p8, p3}| = |{p3, p6, p8}| & |{p6, p1, p3}| = |{p1, p3, p6}| & |{p6, p8, p2}| = |{p2, p6, p8}| & |{p1, p2, p6}| = |{p6, p1, p2}| by ANPROJ_8: 30, Th01;

      then

       A3: |{p6, p1, p8}| = 0 by A1;

      ((( |{p6, p1, p8}| * |{p6, p2, p3}|) - ( |{p6, p1, p2}| * |{p6, p8, p3}|)) + ( |{p6, p1, p3}| * |{p6, p8, p2}|)) = 0 by ANPROJ_8: 28;

      hence thesis by A2, A3;

    end;

    theorem :: PASCAL:23

    

     Th23: |{p2, p4, p9}| = 0 implies ( |{p2, p4, p5}| * |{p2, p9, p7}|) = ( - ( |{p2, p4, p7}| * |{p2, p5, p9}|))

    proof

      assume

       A1: |{p2, p4, p9}| = 0 ;

      ((( |{p2, p4, p5}| * |{p2, p9, p7}|) - ( |{p2, p4, p9}| * |{p2, p5, p7}|)) + ( |{p2, p4, p7}| * |{p2, p5, p9}|)) = 0 by ANPROJ_8: 28;

      hence thesis by A1;

    end;

    theorem :: PASCAL:24

    

     Th24: |{p2, p6, p7}| = 0 implies ( |{p2, p4, p7}| * |{p2, p6, p8}|) = ( - ( |{p2, p4, p6}| * |{p2, p8, p7}|))

    proof

      assume

       A1: |{p2, p6, p7}| = 0 ;

      

       A2: |{p2, p7, p6}| = ( - |{p2, p6, p7}|) & |{p2, p7, p8}| = ( - |{p2, p8, p7}|) by ANPROJ_8: 29;

      ((( |{p2, p4, p7}| * |{p2, p6, p8}|) - ( |{p2, p4, p6}| * |{p2, p7, p8}|)) + ( |{p2, p4, p8}| * |{p2, p7, p6}|)) = 0 by ANPROJ_8: 28;

      hence thesis by A1, A2;

    end;

    theorem :: PASCAL:25

    

     Th25: |{p3, p4, p8}| = 0 implies ( |{p3, p4, p6}| * |{p3, p5, p8}|) = ( |{p3, p4, p5}| * |{p3, p6, p8}|)

    proof

      assume

       A1: |{p3, p4, p8}| = 0 ;

      ((( |{p3, p4, p6}| * |{p3, p5, p8}|) - ( |{p3, p4, p5}| * |{p3, p6, p8}|)) + ( |{p3, p4, p8}| * |{p3, p6, p5}|)) = 0 by ANPROJ_8: 28;

      hence thesis by A1;

    end;

    theorem :: PASCAL:26

    

     Th26: |{p3, p5, p7}| = 0 implies ( |{p1, p3, p5}| * |{p5, p8, p7}|) = ( - ( |{p1, p5, p7}| * |{p3, p5, p8}|))

    proof

      assume

       A1: |{p3, p5, p7}| = 0 ;

      

       A2: |{p3, p5, p7}| = ( - |{p5, p3, p7}|) & |{p5, p8, p3}| = |{p3, p5, p8}| & |{p5, p7, p1}| = |{p1, p5, p7}| & |{p1, p3, p5}| = |{p5, p1, p3}| by ANPROJ_8: 30, Th01;

      then

       A3: |{p5, p3, p7}| = 0 & ( - |{p1, p3, p5}|) = |{p5, p3, p1}| by ANPROJ_8: 29, A1;

      ((( |{p5, p8, p3}| * |{p5, p7, p1}|) - ( |{p5, p8, p7}| * |{p5, p3, p1}|)) + ( |{p5, p8, p1}| * |{p5, p3, p7}|)) = 0 by ANPROJ_8: 28;

      then ( |{p3, p5, p8}| * |{p1, p5, p7}|) = ( |{p5, p8, p7}| * ( - |{p1, p3, p5}|)) by A2, A3;

      hence thesis;

    end;

    theorem :: PASCAL:27

    

     Th27: for r125,r136,r246,r345,r126,r135,r245,r346,r157,r259,r597,r368,r268,r297,r247,r287,r358,r587 be non zero Real st (((r125 * r136) * r246) * r345) = (((r126 * r135) * r245) * r346) & (r157 * r259) = ( - (r125 * r597)) & (r126 * r368) = (r136 * r268) & (r245 * r297) = ( - (r247 * r259)) & (r247 * r268) = ( - (r246 * r287)) & (r346 * r358) = (r345 * r368) & (r135 * r587) = ( - (r157 * r358)) holds (r287 * r597) = (r297 * r587)

    proof

      let r125,r136,r246,r345,r126,r135,r245,r346,r157,r259,r597,r368,r268,r297,r247,r287,r358,r587 be non zero Real;

      assume that

       A1: (((r125 * r136) * r246) * r345) = (((r126 * r135) * r245) * r346) and

       A2: (r157 * r259) = ( - (r125 * r597)) and

       A3: (r126 * r368) = (r136 * r268) and

       A4: (r245 * r297) = ( - (r247 * r259)) and

       A5: (r247 * r268) = ( - (r246 * r287)) and

       A6: (r346 * r358) = (r345 * r368) and

       A7: (r135 * r587) = ( - (r157 * r358));

      reconsider r1 = (((((((((((((r246 * r125) * r247) * r259) * r136) * r268) * r345) * r368) * r157) * r358) * r126) * r135) * r245) * r346), r2 = (((((((((((((r247 * r268) * r157) * r259) * r245) * r126) * r368) * r346) * r358) * r135) * r125) * r136) * r246) * r345) as non zero Real;

      ((((((( - (r287 * r246)) * ( - (r125 * r597))) * ( - (r247 * r259))) * (r136 * r268)) * (r345 * r368)) * ( - (r157 * r358))) * (((r126 * r135) * r245) * r346)) = (((((((r247 * r268) * (r157 * r259)) * (r245 * r297)) * (r126 * r368)) * (r346 * r358)) * (r135 * r587)) * (((r125 * r136) * r246) * r345)) by A1, A2, A3, A4, A5, A6, A7;

      then (r1 * (r287 * r597)) = (r2 * (r297 * r587)) & r1 <> 0 & r2 <> 0 by ORDINAL1:def 14;

      hence thesis by XCMPLX_1: 5;

    end;

    theorem :: PASCAL:28

    

     Th28: p1 = <*1, 0 , 0 *> & p2 = <* 0 , 1, 0 *> & p3 = <* 0 , 0 , 1*> & p4 = <*1, 1, 1*> & p5 = <*e1, e2, e3*> & p6 = <*f1, f2, f3*> & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p5)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p6)) = 0 implies ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p1)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p2)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p3)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p4)) = 0 & ((((r1 * e1) * e2) + ((r2 * e1) * e3)) = (((r1 + r2) * e2) * e3) & (((r1 * f1) * f2) + ((r2 * f1) * f3)) = (((r1 + r2) * f2) * f3))

    proof

      assume that

       A1: p1 = <*1, 0 , 0 *> and

       A2: p2 = <* 0 , 1, 0 *> and

       A3: p3 = <* 0 , 0 , 1*> and

       A4: p4 = <*1, 1, 1*> and

       A5: p5 = <*e1, e2, e3*> and

       A6: p6 = <*f1, f2, f3*> and

       A8: ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p5)) = 0 and

       A9: ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p6)) = 0 ;

      (p1 . 1) = 1 & (p1 . 2) = 0 & (p1 . 3) = 0 by A1, FINSEQ_1: 45;

      hence ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p1)) = 0 ;

      (p2 . 1) = 0 & (p2 . 2) = 1 & (p2 . 3) = 0 by A2, FINSEQ_1: 45;

      hence ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p2)) = 0 ;

      (p3 . 1) = 0 & (p3 . 2) = 0 & (p3 . 3) = 1 by A3, FINSEQ_1: 45;

      hence ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p3)) = 0 ;

      (p4 . 1) = 1 & (p4 . 2) = 1 & (p4 . 3) = 1 by A4, FINSEQ_1: 45;

      hence ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p4)) = 0 ;

      (p5 . 1) = e1 & (p5 . 2) = e2 & (p5 . 3) = e3 by A5, FINSEQ_1: 45;

      hence (((r1 * e1) * e2) + ((r2 * e1) * e3)) = (((r1 + r2) * e2) * e3) by A8;

      (p6 . 1) = f1 & (p6 . 2) = f2 & (p6 . 3) = f3 by A6, FINSEQ_1: 45;

      hence (((r1 * f1) * f2) + ((r2 * f1) * f3)) = (((r1 + r2) * f2) * f3) by A9;

    end;

    theorem :: PASCAL:29

    

     Th29: p1 = <*1, 0 , 0 *> & p2 = <* 0 , 1, 0 *> & p3 = <* 0 , 0 , 1*> & p4 = <*1, 1, 1*> & p5 = <*e1, e2, e3*> & p6 = <*f1, f2, f3*> & |{p1, p2, p5}| <> 0 & |{p1, p3, p6}| <> 0 & |{p2, p4, p6}| <> 0 & |{p3, p4, p5}| <> 0 & |{p1, p2, p6}| <> 0 & |{p1, p3, p5}| <> 0 & |{p2, p4, p5}| <> 0 & |{p3, p4, p6}| <> 0 & |{p1, p5, p7}| <> 0 & |{p2, p5, p9}| <> 0 & |{p5, p9, p7}| <> 0 & |{p3, p6, p8}| <> 0 & |{p2, p6, p8}| <> 0 & |{p2, p9, p7}| <> 0 & |{p2, p4, p7}| <> 0 & |{p2, p8, p7}| <> 0 & |{p3, p5, p8}| <> 0 & |{p5, p8, p7}| <> 0 & (r1 <> 0 or r2 <> 0 ) & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p5)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p6)) = 0 & |{p1, p5, p9}| = 0 & |{p1, p6, p8}| = 0 & |{p2, p4, p9}| = 0 & |{p2, p6, p7}| = 0 & |{p3, p4, p8}| = 0 & |{p3, p5, p7}| = 0 implies ( |{p2, p8, p7}| * |{p5, p9, p7}|) = ( |{p2, p9, p7}| * |{p5, p8, p7}|)

    proof

      assume that

       A1: p1 = <*1, 0 , 0 *> and

       A2: p2 = <* 0 , 1, 0 *> and

       A3: p3 = <* 0 , 0 , 1*> and

       A4: p4 = <*1, 1, 1*> and

       A5: p5 = <*e1, e2, e3*> and

       A6: p6 = <*f1, f2, f3*> and

       A7: |{p1, p2, p5}| <> 0 and

       A8: |{p1, p3, p6}| <> 0 and

       A9: |{p2, p4, p6}| <> 0 and

       A10: |{p3, p4, p5}| <> 0 and

       A11: |{p1, p2, p6}| <> 0 and

       A12: |{p1, p3, p5}| <> 0 and

       A13: |{p2, p4, p5}| <> 0 and

       A14: |{p3, p4, p6}| <> 0 and

       A15: |{p1, p5, p7}| <> 0 and

       A16: |{p2, p5, p9}| <> 0 and

       A17: |{p5, p9, p7}| <> 0 and

       A18: |{p3, p6, p8}| <> 0 and

       A19: |{p2, p6, p8}| <> 0 and

       A20: |{p2, p9, p7}| <> 0 and

       A21: |{p2, p4, p7}| <> 0 and

       A22: |{p2, p8, p7}| <> 0 and

       A23: |{p3, p5, p8}| <> 0 and

       A24: |{p5, p8, p7}| <> 0 and

       A25: (r1 <> 0 or r2 <> 0 ) and

       A26: ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p5)) = 0 and

       A27: ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p6)) = 0 and

       A28: |{p1, p5, p9}| = 0 and

       A29: |{p1, p6, p8}| = 0 and

       A30: |{p2, p4, p9}| = 0 and

       A31: |{p2, p6, p7}| = 0 and

       A32: |{p3, p4, p8}| = 0 and

       A33: |{p3, p5, p7}| = 0 ;

      reconsider r125 = |{p1, p2, p5}|, r136 = |{p1, p3, p6}|, r246 = |{p2, p4, p6}|, r345 = |{p3, p4, p5}|, r126 = |{p1, p2, p6}|, r135 = |{p1, p3, p5}|, r245 = |{p2, p4, p5}|, r346 = |{p3, p4, p6}|, r157 = |{p1, p5, p7}|, r259 = |{p2, p5, p9}|, r597 = |{p5, p9, p7}|, r368 = |{p3, p6, p8}|, r268 = |{p2, p6, p8}|, r297 = |{p2, p9, p7}|, r247 = |{p2, p4, p7}|, r287 = |{p2, p8, p7}|, r358 = |{p3, p5, p8}|, r587 = |{p5, p8, p7}| as non zero Real by A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24;

      p1 = <*(p1 `1 ), (p1 `2 ), (p1 `3 )*> & p2 = <*(p2 `1 ), (p2 `2 ), (p2 `3 )*> & p3 = <*(p3 `1 ), (p3 `2 ), (p3 `3 )*> & p4 = <*(p4 `1 ), (p4 `2 ), (p4 `3 )*> & p5 = <*(p5 `1 ), (p5 `2 ), (p5 `3 )*> & p6 = <*(p6 `1 ), (p6 `2 ), (p6 `3 )*> by EUCLID_5: 3;

      then

      reconsider MABE = <*p1, p2, p5*>, MACF = <*p1, p3, p6*>, MBDF = <*p2, p4, p6*>, MCDE = <*p3, p4, p5*>, MABF = <*p1, p2, p6*>, MACE = <*p1, p3, p5*>, MBDE = <*p2, p4, p5*>, MCDF = <*p3, p4, p6*> as Matrix of 3, F_Real by ANPROJ_8: 19;

      p1 = <*1, 0 , 0 *> & p2 = <* 0 , 1, 0 *> & p3 = <* 0 , 0 , 1*> & p4 = <*1, 1, 1*> & p5 = <*e1, e2, e3*> & p6 = <*f1, f2, f3*> & MABE = <*p1, p2, p5*> & MACF = <*p1, p3, p6*> & MBDF = <*p2, p4, p6*> & MCDE = <*p3, p4, p5*> & MABF = <*p1, p2, p6*> & MACE = <*p1, p3, p5*> & MBDE = <*p2, p4, p5*> & MCDF = <*p3, p4, p6*> by A1, A2, A3, A4, A5, A6;

      then

       A34: ( Det MABE) = |{p1, p2, p5}| & ( Det MACF) = |{p1, p3, p6}| & ( Det MBDF) = |{p2, p4, p6}| & ( Det MCDE) = |{p3, p4, p5}| & ( Det MABF) = |{p1, p2, p6}| & ( Det MACE) = |{p1, p3, p5}| & ( Det MBDE) = |{p2, p4, p5}| & ( Det MCDF) = |{p3, p4, p6}| by Th20;

      now

        MABE = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*e1, e2, e3*>*> & MACF = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*f1, f2, f3*>*> & MBDF = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*f1, f2, f3*>*> & MCDE = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*e1, e2, e3*>*> & MABF = <* <*1, 0 , 0 *>, <* 0 , 1, 0 *>, <*f1, f2, f3*>*> & MACE = <* <*1, 0 , 0 *>, <* 0 , 0 , 1*>, <*e1, e2, e3*>*> & MBDE = <* <* 0 , 1, 0 *>, <*1, 1, 1*>, <*e1, e2, e3*>*> & MCDF = <* <* 0 , 0 , 1*>, <*1, 1, 1*>, <*f1, f2, f3*>*> & (r1 <> 0 or r2 <> 0 ) & ((((r1 * e1) * e2) + ((r2 * e1) * e3)) = (((r1 + r2) * e2) * e3) & (((r1 * f1) * f2) + ((r2 * f1) * f3)) = (((r1 + r2) * f2) * f3)) by A1, A2, A3, A4, A5, A6, A25, A26, A27, Th28;

        then (((( Det MABE) * ( Det MACF)) * ( Det MBDF)) * ( Det MCDE)) = (((( Det MABF) * ( Det MACE)) * ( Det MBDE)) * ( Det MCDF)) by Th19;

        hence (((r125 * r136) * r246) * r345) = (((r126 * r135) * r245) * r346) by A34;

        thus (r157 * r259) = ( - (r125 * r597)) & (r126 * r368) = (r136 * r268) & (r245 * r297) = ( - (r247 * r259)) & (r247 * r268) = ( - (r246 * r287)) & (r346 * r358) = (r345 * r368) & (r135 * r587) = ( - (r157 * r358)) by A28, A29, A30, A31, A32, A33, Th21, Th22, Th23, Th24, Th25, Th26;

      end;

      hence thesis by Th27;

    end;

    theorem :: PASCAL:30

    

     Th30: ( |{p2, p8, p7}| * |{p5, p9, p7}|) = ( |{p2, p9, p7}| * |{p5, p8, p7}|) implies ( |{p7, p2, p5}| * |{p7, p8, p9}|) = 0

    proof

      assume

       A1: ( |{p2, p8, p7}| * |{p5, p9, p7}|) = ( |{p2, p9, p7}| * |{p5, p8, p7}|);

      

       A2: |{p7, p2, p8}| = |{p2, p8, p7}| & |{p7, p5, p9}| = |{p5, p9, p7}| & |{p7, p2, p9}| = |{p2, p9, p7}| & |{p7, p5, p8}| = |{p5, p8, p7}| by Th01;

       |{p7, p5, p8}| = |{p5, p8, p7}| by Th01

      .= ( - |{p8, p5, p7}|) by ANPROJ_8: 30;

      then

       A3: |{p7, p5, p8}| = ( - |{p7, p8, p5}|) by Th01;

      ((( |{p7, p2, p8}| * |{p7, p5, p9}|) - ( |{p7, p2, p5}| * |{p7, p8, p9}|)) + ( |{p7, p2, p9}| * |{p7, p8, p5}|)) = 0 by ANPROJ_8: 28;

      then ((( |{p7, p2, p8}| * |{p7, p5, p9}|) - ( |{p7, p2, p5}| * |{p7, p8, p9}|)) - ( |{p7, p2, p9}| * |{p7, p5, p8}|)) = 0 by A3;

      hence thesis by A2, A1;

    end;

    theorem :: PASCAL:31

    

     Th31: for PCPP be CollProjectiveSpace holds for c1,c2,c3,c4,c5,c6,c7,c8,c9 be Element of PCPP st not (c1,c2,c4) are_collinear & not (c1,c2,c5) are_collinear & not (c1,c6,c4) are_collinear & not (c1,c6,c5) are_collinear & not (c2,c6,c4) are_collinear & not (c3,c4,c2) are_collinear & not (c3,c4,c6) are_collinear & not (c3,c5,c2) are_collinear & not (c3,c5,c6) are_collinear & not (c4,c5,c2) are_collinear & (c1,c4,c7) are_collinear & (c1,c5,c8) are_collinear & (c2,c3,c7) are_collinear & (c2,c5,c9) are_collinear & (c6,c3,c8) are_collinear & (c6,c4,c9) are_collinear holds not (c9,c2,c4) are_collinear & not (c1,c4,c9) are_collinear & not (c2,c3,c9) are_collinear & not (c2,c4,c7) are_collinear & not (c2,c5,c8) are_collinear & not (c2,c9,c8) are_collinear & not (c2,c9,c7) are_collinear & not (c6,c4,c8) are_collinear & not (c6,c5,c8) are_collinear & not (c4,c9,c8) are_collinear & not (c4,c9,c7) are_collinear

    proof

      let PCPP be CollProjectiveSpace;

      let c1,c2,c3,c4,c5,c6,c7,c8,c9 be Element of PCPP;

      assume that

       A11: not (c1,c2,c4) are_collinear and

       A12: not (c1,c2,c5) are_collinear and

       A13: not (c1,c6,c4) are_collinear and

       A14: not (c1,c6,c5) are_collinear and

       A15: not (c2,c6,c4) are_collinear and

       A16: not (c3,c4,c2) are_collinear and

       A17: not (c3,c4,c6) are_collinear and

       A18: not (c3,c5,c2) are_collinear and

       A19: not (c3,c5,c6) are_collinear and

       A20: not (c4,c5,c2) are_collinear and

       A21: (c1,c4,c7) are_collinear and

       A22: (c1,c5,c8) are_collinear and

       A23: (c2,c3,c7) are_collinear and

       A24: (c2,c5,c9) are_collinear and

       A25: (c6,c3,c8) are_collinear and

       A26: (c6,c4,c9) are_collinear and

       A27: (c9,c2,c4) are_collinear or (c1,c4,c9) are_collinear or (c2,c3,c9) are_collinear or (c2,c4,c7) are_collinear or (c2,c5,c8) are_collinear or (c2,c9,c8) are_collinear or (c2,c9,c7) are_collinear or (c6,c4,c8) are_collinear or (c6,c5,c8) are_collinear or (c4,c9,c8) are_collinear or (c4,c9,c7) are_collinear ;

      

       A34: for v102,v103,v100,v104 be Element of PCPP holds v100 = v104 or not (v104,v100,v102) are_collinear or not (v104,v100,v103) are_collinear or (v102,v103,v104) are_collinear

      proof

        let v102,v103,v100,v104 be Element of PCPP;

        (v104,v100,v104) are_collinear by COLLSP: 5;

        hence thesis by COLLSP: 3;

      end;

      

       A38: for v102,v104,v100,v103 be Element of PCPP holds v100 = v103 or not (v103,v100,v102) are_collinear or not (v103,v100,v104) are_collinear or (v102,v103,v104) are_collinear

      proof

        let v102,v104,v100,v103 be Element of PCPP;

        (v103,v100,v103) are_collinear by COLLSP: 5;

        hence thesis by COLLSP: 3;

      end;

      

       A47: not c5 = c2 by COLLSP: 2, A12;

      

       A49: not (c6,c4,c1) are_collinear by HESSENBE: 1, A13;

      

       A51: not (c4,c1,c6) are_collinear by HESSENBE: 1, A13;

      

       A54: not c6 = c4 by A13, COLLSP: 2;

      

       A61: not (c6,c4,c2) are_collinear by HESSENBE: 1, A15;

      

       A67: not (c6,c3,c4) are_collinear by HESSENBE: 1, A17;

      

       A69: not (c2,c3,c5) are_collinear by HESSENBE: 1, A18;

      

       A75: (c4,c7,c1) are_collinear by A21, HESSENBE: 1;

      

       A79: (c2,c7,c3) are_collinear by A23, COLLSP: 4;

      

       A81: (c9,c2,c5) are_collinear by A24, HESSENBE: 1;

      

       A83: (c2,c9,c5) are_collinear by A24, COLLSP: 4;

      

       A85: (c6,c8,c3) are_collinear by A25, COLLSP: 4;

      

       A89: (c4,c9,c6) are_collinear by A26, HESSENBE: 1;

      

       A98: (c1,c4,c9) are_collinear or (c2,c3,c9) are_collinear or (c2,c4,c7) are_collinear or (c2,c5,c8) are_collinear or (c2,c9,c8) are_collinear or (c2,c9,c7) are_collinear or (c6,c4,c8) are_collinear or (c6,c5,c8) are_collinear or (c4,c9,c8) are_collinear or (c4,c9,c7) are_collinear or (c9,c4,c2) are_collinear by A27, COLLSP: 4;

      

       A101: for v102,v103,v104,v101 be Element of PCPP holds v104 = v101 or not (v101,v104,v102) are_collinear or not (v101,v104,v103) are_collinear or (v102,v103,v104) are_collinear

      proof

        let v102,v103,v104,v101 be Element of PCPP;

        (v101,v104,v104) are_collinear by COLLSP: 2;

        hence thesis by COLLSP: 3;

      end;

      

       A105: for v103,v104,v102,v101 be Element of PCPP holds v102 = v101 or not (v101,v102,v103) are_collinear or not (v101,v102,v104) are_collinear or (v102,v103,v104) are_collinear

      proof

        let v103,v104,v102,v101 be Element of PCPP;

        (v101,v102,v102) are_collinear by COLLSP: 2;

        hence thesis by COLLSP: 3;

      end;

      

       A121: (c7,c4,c1) are_collinear by A21, HESSENBE: 1;

      

       A124: for v2,v101,v100 be Element of PCPP holds v101 = v100 or not (v100,v101,v2) are_collinear or (v2,v101,v100) are_collinear

      proof

        let v2,v101,v100 be Element of PCPP;

        v101 = v100 or not (v100,v101,v2) are_collinear or not (v100,v101,v101) are_collinear or (v2,v101,v100) are_collinear by A34;

        hence thesis by COLLSP: 2;

      end;

      

       A130: (c2,c5,c5) are_collinear by COLLSP: 2;

      

       A133: not (c2,c5,c4) are_collinear by A130, A47, A34, A20;

      

       A144: (c8,c5,c1) are_collinear by A22, HESSENBE: 1;

      

       A147: for v0 be Element of PCPP holds c7 = c4 or not (c4,c7,v0) are_collinear or (v0,c4,c1) are_collinear by A75, A38;

      

       A158: for v0 be Element of PCPP holds c7 = c2 or not (c2,c7,v0) are_collinear or (c2,c3,v0) are_collinear by A79, HESSENBE: 2;

      

       A161: for v0 be Element of PCPP holds c9 = c2 or not (c2,c9,v0) are_collinear or (c2,v0,c5) are_collinear by A83, HESSENBE: 2;

      

       A169: (c9,c4,c6) are_collinear by A26, HESSENBE: 1;

      

       A175: for v0 be Element of PCPP holds c9 = c4 or not (c4,c9,v0) are_collinear or (c4,v0,c6) are_collinear by A89, HESSENBE: 2;

      

       A203: c5 = c6 or not (c6,c5,c8) are_collinear or (c8,c5,c6) are_collinear by A124;

      

       A213: c9 = c4 or not (c4,c9,c8) are_collinear or (c6,c8,c4) are_collinear by A89, A34;

      

       A234: c5 = c2 or not (c2,c5,c8) are_collinear or (c8,c5,c2) are_collinear by A124;

      

       A241: c4 = c2 or not (c2,c4,c7) are_collinear or (c7,c4,c2) are_collinear by A124;

      

       A247: c9 = c4 or (c1,c4,c9) are_collinear or (c2,c3,c9) are_collinear or c8 = c5 or c8 = c6 or c7 = c4 or c9 = c2 or c7 = c2 by A11, A121, A105, COLLSP: 2, A12, A69, A158, A49, A175, A67, A54, A26, A14, A144, A15, A98, A169, A101, A203, A213, A85, A147, A83, HESSENBE: 2, A161, A241, A234;

      

       A248: not (c2,c3,c9) are_collinear or (c9,c2,c3) are_collinear by HESSENBE: 1;

      c4 = c1 or not (c1,c4,c9) are_collinear or (c9,c4,c1) are_collinear by A124;

      hence contradiction by A11, A21, A16, HESSENBE: 1, A23, A19, A25, A14, A22, A61, A26, A133, A24, A51, A169, COLLSP: 2, A69, A247, A248, A81, A105;

    end;

    reserve P1,P2,P3,P4,P5,P6,P7,P8,P9 for Point of ( ProjectiveSpace ( TOP-REAL 3)),

a,b,c,d,e,f for Real;

    definition

      let P1,P2,P3,P4,P5,P6,P7,P8,P9 be Point of ( ProjectiveSpace ( TOP-REAL 3));

      :: PASCAL:def4

      pred P1,P2,P3,P4,P5,P6,P7,P8,P9 are_in_Pascal_configuration means not (P1,P2,P4) are_collinear & not (P1,P3,P4) are_collinear & not (P2,P3,P4) are_collinear & not (P1,P2,P5) are_collinear & not (P1,P2,P6) are_collinear & not (P1,P3,P5) are_collinear & not (P1,P3,P6) are_collinear & not (P2,P4,P5) are_collinear & not (P2,P4,P6) are_collinear & not (P3,P4,P5) are_collinear & not (P3,P4,P6) are_collinear & not (P2,P3,P5) are_collinear & not (P2,P3,P6) are_collinear & not (P4,P5,P1) are_collinear & not (P4,P6,P1) are_collinear & not (P5,P6,P1) are_collinear & not (P5,P6,P2) are_collinear & (P1,P5,P9) are_collinear & (P1,P6,P8) are_collinear & (P2,P4,P9) are_collinear & (P2,P6,P7) are_collinear & (P3,P4,P8) are_collinear & (P3,P5,P7) are_collinear ;

    end

    theorem :: PASCAL:32

    

     Th32: (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration implies not (P7,P2,P5) are_collinear & not (P1,P5,P7) are_collinear & not (P2,P4,P7) are_collinear & not (P2,P5,P9) are_collinear & not (P2,P6,P8) are_collinear & not (P2,P7,P8) are_collinear & not (P2,P7,P9) are_collinear & not (P3,P5,P8) are_collinear & not (P3,P6,P8) are_collinear & not (P5,P7,P8) are_collinear & not (P5,P7,P9) are_collinear

    proof

      assume

       A1: (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration ;

      assume

       A2: not ( not (P7,P2,P5) are_collinear & not (P1,P5,P7) are_collinear & not (P2,P4,P7) are_collinear & not (P2,P5,P9) are_collinear & not (P2,P6,P8) are_collinear & not (P2,P7,P8) are_collinear & not (P2,P7,P9) are_collinear & not (P3,P5,P8) are_collinear & not (P3,P6,P8) are_collinear & not (P5,P7,P8) are_collinear & not (P5,P7,P9) are_collinear );

       not (P1,P2,P4) are_collinear & not (P1,P2,P5) are_collinear & not (P1,P2,P6) are_collinear & not (P1,P3,P4) are_collinear & not (P1,P3,P5) are_collinear & not (P1,P3,P6) are_collinear & not (P2,P3,P4) are_collinear & not (P2,P3,P5) are_collinear & not (P4,P5,P1) are_collinear & not (P4,P5,P2) are_collinear & not (P4,P5,P3) are_collinear & not (P4,P6,P2) are_collinear & not (P4,P6,P3) are_collinear & not (P5,P6,P2) are_collinear & (P1,P5,P9) are_collinear & (P1,P6,P8) are_collinear & (P2,P4,P9) are_collinear & (P2,P6,P7) are_collinear & (P3,P4,P8) are_collinear & (P3,P5,P7) are_collinear by A1, ANPROJ_8: 57, HESSENBE: 1;

      hence contradiction by A2, ANPROJ_8: 57, Th31;

    end;

    theorem :: PASCAL:33

    

     Th33: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) & {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) & not (P1,P2,P3) are_collinear & not (P1,P2,P4) are_collinear & not (P1,P3,P4) are_collinear & not (P2,P3,P4) are_collinear & not (P7,P2,P5) are_collinear & not (P1,P2,P5) are_collinear & not (P1,P2,P6) are_collinear & not (P1,P3,P5) are_collinear & not (P1,P3,P6) are_collinear & not (P1,P5,P7) are_collinear & not (P2,P4,P5) are_collinear & not (P2,P4,P6) are_collinear & not (P2,P4,P7) are_collinear & not (P2,P5,P9) are_collinear & not (P2,P6,P8) are_collinear & not (P2,P7,P8) are_collinear & not (P2,P7,P9) are_collinear & not (P3,P4,P5) are_collinear & not (P3,P4,P6) are_collinear & not (P3,P5,P8) are_collinear & not (P3,P6,P8) are_collinear & not (P5,P7,P8) are_collinear & not (P5,P7,P9) are_collinear & (P1,P5,P9) are_collinear & (P1,P6,P8) are_collinear & (P2,P4,P9) are_collinear & (P2,P6,P7) are_collinear & (P3,P4,P8) are_collinear & (P3,P5,P7) are_collinear implies (P7,P8,P9) are_collinear

    proof

      assume that

       A1: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) and

       A2: {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) and

       A3: not ((P1,P2,P3) are_collinear ) and

       A4: not ((P1,P2,P4) are_collinear ) and

       A5: not ((P1,P3,P4) are_collinear ) and

       A6: not ((P2,P3,P4) are_collinear ) and

       A7: not (P7,P2,P5) are_collinear and

       A8: not (P1,P2,P5) are_collinear and

       A9: not (P1,P2,P6) are_collinear and

       A10: not (P1,P3,P5) are_collinear and

       A11: not (P1,P3,P6) are_collinear and

       A12: not (P1,P5,P7) are_collinear and

       A13: not (P2,P4,P5) are_collinear and

       A14: not (P2,P4,P6) are_collinear and

       A15: not (P2,P4,P7) are_collinear and

       A16: not (P2,P5,P9) are_collinear and

       A17: not (P2,P6,P8) are_collinear and

       A18: not (P2,P7,P8) are_collinear and

       A19: not (P2,P7,P9) are_collinear and

       A20: not (P3,P4,P5) are_collinear and

       A21: not (P3,P4,P6) are_collinear and

       A22: not (P3,P5,P8) are_collinear and

       A23: not (P3,P6,P8) are_collinear and

       A24: not (P5,P7,P8) are_collinear and

       A25: not (P5,P7,P9) are_collinear and

       A26: (P1,P5,P9) are_collinear and

       A27: (P1,P6,P8) are_collinear and

       A28: (P2,P4,P9) are_collinear and

       A29: (P2,P6,P7) are_collinear and

       A30: (P3,P4,P8) are_collinear and

       A31: (P3,P5,P7) are_collinear ;

      consider N be invertible Matrix of 3, F_Real such that

       A32: (( homography N) . P1) = Dir100 and

       A33: (( homography N) . P2) = Dir010 and

       A34: (( homography N) . P3) = Dir001 and

       A35: (( homography N) . P4) = Dir111 by A3, A4, A5, A6, ANPROJ_9: 30;

      consider u5 be Point of ( TOP-REAL 3) such that

       A36: u5 is non zero and

       A37: (( homography N) . P5) = ( Dir u5) by ANPROJ_1: 26;

      reconsider p51 = (u5 . 1), p52 = (u5 . 2), p53 = (u5 . 3) as Real;

      

       A38: (u5 `1 ) = (u5 . 1) & (u5 `2 ) = (u5 . 2) & (u5 `3 ) = (u5 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A39: (( homography N) . P5) = ( Dir |[p51, p52, p53]|) by A37, EUCLID_5: 3;

      consider u6 be Point of ( TOP-REAL 3) such that

       A40: u6 is non zero and

       A41: (( homography N) . P6) = ( Dir u6) by ANPROJ_1: 26;

      reconsider p61 = (u6 . 1), p62 = (u6 . 2), p63 = (u6 . 3) as Real;

      

       A42: (u6 `1 ) = (u6 . 1) & (u6 `2 ) = (u6 . 2) & (u6 `3 ) = (u6 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A43: (( homography N) . P6) = ( Dir |[p61, p62, p63]|) by A41, EUCLID_5: 3;

      consider u7 be Point of ( TOP-REAL 3) such that

       A44: u7 is non zero and

       A45: (( homography N) . P7) = ( Dir u7) by ANPROJ_1: 26;

      reconsider p71 = (u7 . 1), p72 = (u7 . 2), p73 = (u7 . 3) as Real;

      

       A46: (u7 `1 ) = (u7 . 1) & (u7 `2 ) = (u7 . 2) & (u7 `3 ) = (u7 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A47: (( homography N) . P7) = ( Dir |[p71, p72, p73]|) by A45, EUCLID_5: 3;

      consider u8 be Point of ( TOP-REAL 3) such that

       A48: u8 is non zero and

       A49: (( homography N) . P8) = ( Dir u8) by ANPROJ_1: 26;

      reconsider p81 = (u8 . 1), p82 = (u8 . 2), p83 = (u8 . 3) as Real;

      

       A50: (u8 `1 ) = (u8 . 1) & (u8 `2 ) = (u8 . 2) & (u8 `3 ) = (u8 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A51: (( homography N) . P8) = ( Dir |[p81, p82, p83]|) by A49, EUCLID_5: 3;

      consider u9 be Point of ( TOP-REAL 3) such that

       A52: u9 is non zero and

       A53: (( homography N) . P9) = ( Dir u9) by ANPROJ_1: 26;

      reconsider p91 = (u9 . 1), p92 = (u9 . 2), p93 = (u9 . 3) as Real;

      

       A54: (u9 `1 ) = (u9 . 1) & (u9 `2 ) = (u9 . 2) & (u9 `3 ) = (u9 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A55: (( homography N) . P9) = ( Dir |[p91, p92, p93]|) by A53, EUCLID_5: 3;

      

       A56: P1 in {P1, P2, P3, P4, P5, P6} & P2 in {P1, P2, P3, P4, P5, P6} & P3 in {P1, P2, P3, P4, P5, P6} & P4 in {P1, P2, P3, P4, P5, P6} & P5 in {P1, P2, P3, P4, P5, P6} & P6 in {P1, P2, P3, P4, P5, P6} by ENUMSET1:def 4;

      consider a2,b2,c2,d2,e2,f2 be Real such that

       A57: not (a2 = 0 & b2 = 0 & c2 = 0 & d2 = 0 & e2 = 0 & f2 = 0 ) and

       A58: (( homography N) . P1) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A59: (( homography N) . P2) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A60: (( homography N) . P3) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A61: (( homography N) . P4) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A62: (( homography N) . P5) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A63: (( homography N) . P6) in ( conic (a2,b2,c2,d2,e2,f2)) by A56, A2, A1, Th17;

      consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

       A64: ( Dir |[1, 0 , 0 ]|) = P and

       A65: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A32, A58;

      

       A66: ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 0 , 0 ]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 1, 0 ]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 0 , 1]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 1, 1]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[p51, p52, p53]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[p61, p62, p63]|)) = 0

      proof

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 0 , 0 ]|)) = 0 by A64, A65, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A67: ( Dir |[ 0 , 1, 0 ]|) = P and

         A68: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A33, A59;

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 1, 0 ]|)) = 0 by A67, A68, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A69: ( Dir |[ 0 , 0 , 1]|) = P and

         A70: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A34, A60;

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 0 , 1]|)) = 0 by A69, A70, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A71: ( Dir |[1, 1, 1]|) = P and

         A72: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A35, A61;

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 1, 1]|)) = 0 by A71, A72, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A73: ( Dir |[p51, p52, p53]|) = P and

         A74: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A39, A62;

         |[p51, p52, p53]| is non zero & ( Dir |[p51, p52, p53]|) = P by A73, A36, A38, EUCLID_5: 3;

        hence ( qfconic (a2,b2,c2,d2,e2,f2, |[p51, p52, p53]|)) = 0 by A74;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A75: ( Dir |[p61, p62, p63]|) = P and

         A76: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A43, A63;

         |[p61, p62, p63]| is non zero & ( Dir |[p61, p62, p63]|) = P by A75, A42, EUCLID_5: 3, A40;

        hence ( qfconic (a2,b2,c2,d2,e2,f2, |[p61, p62, p63]|)) = 0 by A76;

      end;

      reconsider a2f = a2, b2f = b2, c2f = c2, d2f = d2, e2f = e2, f2f = f2 as Element of F_Real by XREAL_0:def 1;

      ( qfconic (a2f,b2f,c2f,d2f,e2,f2f, |[1, 0 , 0 ]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[ 0 , 1, 0 ]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[ 0 , 0 , 1]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[1, 1, 1]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[p51, p52, p53]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[p61, p62, p63]|)) = 0 by A66;

      then a2f = 0 & b2f = 0 & c2f = 0 by Th18;

      then

       A77: a2f = 0 & b2f = 0 & c2f = 0 & ((d2f + e2f) + f2f) = 0 by A66, Th18;

      reconsider r1 = d2, r2 = e2 as Real;

      reconsider p71, p72, p73, p81, p82, p83, p91, p92, p93 as Element of F_Real by XREAL_0:def 1;

       |[1, 0 , 0 ]| = <*1, 0 , 0 *> & <* 0 , 1, 0 *> = |[ 0 , 1, 0 ]| & <* 0 , 0 , 1*> = |[ 0 , 0 , 1]| & <*1, 1, 1*> = |[1, 1, 1]| & <*p51, p52, p53*> = |[p51, p52, p53]| & <*p61, p62, p63*> = |[p61, p62, p63]| & <*p71, p72, p73*> = |[p71, p72, p73]| & <*p81, p82, p83*> = |[p81, p82, p83]| & <*p91, p92, p93*> = |[p91, p92, p93]|;

      then

      reconsider p1 = <*1, 0 , 0 *>, p2 = <* 0 , 1, 0 *>, p3 = <* 0 , 0 , 1*>, p4 = <*1, 1, 1*>, p5 = <*p51, p52, p53*>, p6 = <*p61, p62, p63*>, p7 = <*p71, p72, p73*>, p8 = <*p81, p82, p83*>, p9 = <*p91, p92, p93*> as Point of ( TOP-REAL 3);

      

       A82: u5 = |[p51, p52, p53]| by EUCLID_5: 3, A38;

      

       A83: u6 = |[p61, p62, p63]| by A42, EUCLID_5: 3;

      

       A84: p7 is non zero by A44, A46, EUCLID_5: 3;

      

       A85: p8 is non zero by A48, A50, EUCLID_5: 3;

      

       A86: p9 is non zero by A52, A54, EUCLID_5: 3;

      

       A87: (r1 <> 0 or r2 <> 0 ) & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p5)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,r2,( - (r1 + r2)),p6)) = 0 by A77, A66, A57;

      

       A88: |{p7, p2, p5}| <> 0

      proof

        

         A89: not ((( homography N) . P7),(( homography N) . P2),(( homography N) . P5)) are_collinear by A7, ANPROJ_8: 102;

        (( homography N) . P7) = ( Dir p7) & (( homography N) . P2) = ( Dir p2) & (( homography N) . P5) = ( Dir p5) by A33, A38, A37, EUCLID_5: 3, A45, A46;

        hence thesis by ANPROJ_8: 43, A89, A84, ANPROJ_9: 10, A82, A36, ANPROJ_2: 23;

      end;

      

       A90: p51 is Element of F_Real & p52 is Element of F_Real & p53 is Element of F_Real & p61 is Element of F_Real & p62 is Element of F_Real & p63 is Element of F_Real by XREAL_0:def 1;

      now

        thus |{p1, p2, p5}| <> 0

        proof

           not ((( homography N) . P1),(( homography N) . P2),(( homography N) . P5)) are_collinear by A8, ANPROJ_8: 102;

          hence thesis by A32, A33, A37, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, ANPROJ_2: 23;

        end;

        thus |{p1, p2, p6}| <> 0

        proof

           not ((( homography N) . P1),(( homography N) . P2),(( homography N) . P6)) are_collinear by A9, ANPROJ_8: 102;

          hence thesis by A32, A33, A41, ANPROJ_8: 43, A83, A40, ANPROJ_9: 10, ANPROJ_2: 23;

        end;

        thus |{p1, p3, p5}| <> 0

        proof

           not ((( homography N) . P1),(( homography N) . P3),(( homography N) . P5)) are_collinear by A10, ANPROJ_8: 102;

          hence thesis by A34, A32, A37, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, ANPROJ_2: 23;

        end;

        thus |{p1, p3, p6}| <> 0

        proof

           not ((( homography N) . P1),(( homography N) . P3),(( homography N) . P6)) are_collinear by A11, ANPROJ_8: 102;

          hence thesis by A32, A41, A34, ANPROJ_8: 43, A83, A40, ANPROJ_9: 10, ANPROJ_2: 23;

        end;

        thus |{p1, p5, p7}| <> 0

        proof

           not ((( homography N) . P1),(( homography N) . P5),(( homography N) . P7)) are_collinear by A12, ANPROJ_8: 102;

          hence thesis by A32, A37, A47, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, A84, ANPROJ_2: 23;

        end;

        thus |{p2, p4, p5}| <> 0

        proof

           not ((( homography N) . P2),(( homography N) . P4),(( homography N) . P5)) are_collinear by A13, ANPROJ_8: 102;

          hence thesis by A33, A37, A35, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, ANPROJ_2: 23;

        end;

        thus |{p2, p4, p6}| <> 0

        proof

           not ((( homography N) . P2),(( homography N) . P4),(( homography N) . P6)) are_collinear by A14, ANPROJ_8: 102;

          hence thesis by A33, A41, A35, ANPROJ_8: 43, ANPROJ_9: 10, A83, A40, ANPROJ_2: 23;

        end;

        thus |{p2, p4, p7}| <> 0

        proof

           not ((( homography N) . P2),(( homography N) . P4),(( homography N) . P7)) are_collinear by A15, ANPROJ_8: 102;

          hence thesis by A33, A47, A35, ANPROJ_8: 43, ANPROJ_9: 10, A84, ANPROJ_2: 23;

        end;

        thus |{p2, p5, p9}| <> 0

        proof

           not ((( homography N) . P2),(( homography N) . P5),(( homography N) . P9)) are_collinear by A16, ANPROJ_8: 102;

          hence thesis by A33, A37, A55, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, A86, ANPROJ_2: 23;

        end;

        thus |{p2, p6, p8}| <> 0

        proof

           not ((( homography N) . P2),(( homography N) . P6),(( homography N) . P8)) are_collinear by A17, ANPROJ_8: 102;

          hence thesis by A33, A41, A51, ANPROJ_8: 43, ANPROJ_9: 10, A83, A40, A85, ANPROJ_2: 23;

        end;

        thus |{p2, p8, p7}| <> 0

        proof

          

           A91: |{p2, p8, p7}| = ( - |{p2, p7, p8}|) by ANPROJ_8: 29;

           not ((( homography N) . P2),(( homography N) . P7),(( homography N) . P8)) are_collinear by A18, ANPROJ_8: 102;

          hence thesis by A33, A47, A51, A91, ANPROJ_8: 43, ANPROJ_9: 10, A84, A85, ANPROJ_2: 23;

        end;

        thus |{p2, p9, p7}| <> 0

        proof

          

           A92: |{p2, p9, p7}| = ( - |{p2, p7, p9}|) by ANPROJ_8: 29;

           not ((( homography N) . P2),(( homography N) . P7),(( homography N) . P9)) are_collinear by A19, ANPROJ_8: 102;

          hence thesis by A92, ANPROJ_8: 43, A33, A47, A55, ANPROJ_9: 10, A84, A86, ANPROJ_2: 23;

        end;

        thus |{p3, p4, p5}| <> 0

        proof

           not ((( homography N) . P3),(( homography N) . P4),(( homography N) . P5)) are_collinear by A20, ANPROJ_8: 102;

          hence thesis by A34, A35, A37, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, ANPROJ_2: 23;

        end;

        thus |{p3, p4, p6}| <> 0

        proof

           not ((( homography N) . P3),(( homography N) . P4),(( homography N) . P6)) are_collinear by A21, ANPROJ_8: 102;

          hence thesis by A34, A35, A41, ANPROJ_8: 43, ANPROJ_9: 10, A83, A40, ANPROJ_2: 23;

        end;

        thus |{p3, p5, p8}| <> 0

        proof

           not ((( homography N) . P3),(( homography N) . P5),(( homography N) . P8)) are_collinear by A22, ANPROJ_8: 102;

          hence thesis by A34, A37, A51, ANPROJ_8: 43, ANPROJ_9: 10, A82, A36, A85, ANPROJ_2: 23;

        end;

        thus |{p3, p6, p8}| <> 0

        proof

           not ((( homography N) . P3),(( homography N) . P6),(( homography N) . P8)) are_collinear by A23, ANPROJ_8: 102;

          hence thesis by ANPROJ_8: 43, A34, A41, A51, ANPROJ_9: 10, A83, A40, A85, ANPROJ_2: 23;

        end;

        

         A93: |{p5, p8, p7}| = ( - |{p5, p7, p8}|) by ANPROJ_8: 29;

        thus |{p5, p7, p8}| <> 0

        proof

           not ((( homography N) . P5),(( homography N) . P7),(( homography N) . P8)) are_collinear by A24, ANPROJ_8: 102;

          hence thesis by ANPROJ_8: 43, A37, A47, A51, A82, A36, A84, A85, ANPROJ_2: 23;

        end;

        hence |{p5, p8, p7}| <> 0 by A93;

        

         A94: |{p5, p9, p7}| = ( - |{p5, p7, p9}|) by ANPROJ_8: 29;

         |{p5, p7, p9}| <> 0

        proof

           not ((( homography N) . P5),(( homography N) . P7),(( homography N) . P9)) are_collinear by A25, ANPROJ_8: 102;

          hence thesis by A37, A47, A55, ANPROJ_8: 43, A82, A36, A84, A86, ANPROJ_2: 23;

        end;

        hence |{p5, p9, p7}| <> 0 by A94;

        thus |{p1, p5, p9}| = 0 & |{p1, p6, p8}| = 0 & |{p2, p4, p9}| = 0 & |{p2, p6, p7}| = 0 & |{p3, p4, p8}| = 0 & |{p3, p5, p7}| = 0

        proof

          thus |{p1, p5, p9}| = 0

          proof

            consider u,v,w be Element of ( TOP-REAL 3) such that

             A95: (( homography N) . P1) = ( Dir u) and

             A96: (( homography N) . P5) = ( Dir v) and

             A97: (( homography N) . P9) = ( Dir w) and

             A98: u is non zero and

             A99: v is non zero and

             A100: w is non zero and

             A101: (u,v,w) are_LinDep by A26, ANPROJ_8: 102, ANPROJ_2: 23;

             [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A98, A99, A100, A101, ANPROJ_1: 25;

            then (p1,p5,p9) are_LinDep by A32, A37, A55, A95, A96, A97, ANPROJ_9: 10, A82, A36, A86, ANPROJ_1: 25;

            hence thesis by ANPROJ_8: 43;

          end;

          thus |{p1, p6, p8}| = 0

          proof

            consider u,v,w be Element of ( TOP-REAL 3) such that

             A102: (( homography N) . P1) = ( Dir u) and

             A103: (( homography N) . P6) = ( Dir v) and

             A104: (( homography N) . P8) = ( Dir w) and

             A105: u is non zero and

             A106: v is non zero and

             A107: w is non zero and

             A108: (u,v,w) are_LinDep by A27, ANPROJ_8: 102, ANPROJ_2: 23;

            

             A109: [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A105, A106, A107, A108, ANPROJ_1: 25;

            (p1,p6,p8) are_LinDep by A32, A41, A51, A102, A103, A104, A109, ANPROJ_9: 10, A83, A40, A85, ANPROJ_1: 25;

            hence thesis by ANPROJ_8: 43;

          end;

          thus |{p2, p4, p9}| = 0

          proof

            consider u,v,w be Element of ( TOP-REAL 3) such that

             A110: (( homography N) . P2) = ( Dir u) and

             A111: (( homography N) . P4) = ( Dir v) and

             A112: (( homography N) . P9) = ( Dir w) and

             A113: u is non zero and

             A114: v is non zero and

             A115: w is non zero and

             A116: (u,v,w) are_LinDep by A28, ANPROJ_8: 102, ANPROJ_2: 23;

             [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A113, A114, A115, A116, ANPROJ_1: 25;

            then (p2,p4,p9) are_LinDep by A33, A35, A55, A110, A111, A112, ANPROJ_9: 10, A86, ANPROJ_1: 25;

            hence thesis by ANPROJ_8: 43;

          end;

          thus |{p2, p6, p7}| = 0

          proof

            consider u,v,w be Element of ( TOP-REAL 3) such that

             A117: (( homography N) . P2) = ( Dir u) and

             A118: (( homography N) . P6) = ( Dir v) and

             A119: (( homography N) . P7) = ( Dir w) and

             A120: u is non zero and

             A121: v is non zero and

             A122: w is non zero and

             A123: (u,v,w) are_LinDep by A29, ANPROJ_8: 102, ANPROJ_2: 23;

            

             A124: [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A120, A121, A122, A123, ANPROJ_1: 25;

            (p2,p6,p7) are_LinDep by A33, A41, A47, A117, A118, A119, A124, ANPROJ_9: 10, A83, A40, A84, ANPROJ_1: 25;

            hence thesis by ANPROJ_8: 43;

          end;

          thus |{p3, p4, p8}| = 0

          proof

            consider u,v,w be Element of ( TOP-REAL 3) such that

             A125: (( homography N) . P3) = ( Dir u) and

             A126: (( homography N) . P4) = ( Dir v) and

             A127: (( homography N) . P8) = ( Dir w) and

             A128: u is non zero and

             A129: v is non zero and

             A130: w is non zero and

             A131: (u,v,w) are_LinDep by A30, ANPROJ_8: 102, ANPROJ_2: 23;

             [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A128, A129, A130, A131, ANPROJ_1: 25;

            then (p3,p4,p8) are_LinDep by A34, A35, A51, A125, A126, A127, ANPROJ_9: 10, A85, ANPROJ_1: 25;

            hence thesis by ANPROJ_8: 43;

          end;

          thus |{p3, p5, p7}| = 0

          proof

            consider u,v,w be Element of ( TOP-REAL 3) such that

             A132: (( homography N) . P3) = ( Dir u) and

             A133: (( homography N) . P5) = ( Dir v) and

             A134: (( homography N) . P7) = ( Dir w) and

             A135: u is non zero and

             A136: v is non zero and

             A137: w is non zero and

             A138: (u,v,w) are_LinDep by A31, ANPROJ_8: 102, ANPROJ_2: 23;

             [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A135, A136, A137, A138, ANPROJ_1: 25;

            then (p3,p5,p7) are_LinDep by A34, A37, A47, A132, A133, A134, ANPROJ_9: 10, A82, A36, A84, ANPROJ_1: 25;

            hence thesis by ANPROJ_8: 43;

          end;

        end;

      end;

      then ( |{p2, p8, p7}| * |{p5, p9, p7}|) = ( |{p2, p9, p7}| * |{p5, p8, p7}|) by A90, A87, Th29;

      then ( |{p7, p2, p5}| * |{p7, p8, p9}|) = 0 by Th30;

      then |{p7, p8, p9}| = 0 by A88, XCMPLX_1: 6;

      then

       A139: (p7,p8,p9) are_LinDep by ANPROJ_8: 43;

      (( homography N) . P7) = ( Dir p7) & (( homography N) . P8) = ( Dir p8) & (( homography N) . P9) = ( Dir p9) & p7 is non zero & p8 is non zero & p9 is non zero by A52, A54, EUCLID_5: 3, A44, A46, A50, A48, A45, A49, A53;

      hence thesis by A139, ANPROJ_2: 23, ANPROJ_8: 102;

    end;

    theorem :: PASCAL:34

    

     Th34: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) & {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) & not (P1,P2,P3) are_collinear & (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration implies (P7,P8,P9) are_collinear

    proof

      assume that

       A1: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) and

       A2: {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) and

       A3: not (P1,P2,P3) are_collinear & (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration ;

       not ((P1,P2,P3) are_collinear ) & not ((P1,P2,P4) are_collinear ) & not ((P1,P3,P4) are_collinear ) & not ((P2,P3,P4) are_collinear ) & not (P7,P2,P5) are_collinear & not (P1,P2,P5) are_collinear & not (P1,P2,P6) are_collinear & not (P1,P3,P5) are_collinear & not (P1,P3,P6) are_collinear & not (P1,P5,P7) are_collinear & not (P2,P4,P5) are_collinear & not (P2,P4,P6) are_collinear & not (P2,P4,P7) are_collinear & not (P2,P5,P9) are_collinear & not (P2,P6,P8) are_collinear & not (P2,P7,P8) are_collinear & not (P2,P7,P9) are_collinear & not (P3,P4,P5) are_collinear & not (P3,P4,P6) are_collinear & not (P3,P5,P8) are_collinear & not (P3,P6,P8) are_collinear & not (P5,P7,P8) are_collinear & not (P5,P7,P9) are_collinear & (P1,P5,P9) are_collinear & (P1,P6,P8) are_collinear & (P2,P4,P9) are_collinear & (P2,P6,P7) are_collinear & (P3,P4,P8) are_collinear & (P3,P5,P7) are_collinear by A3, Th32;

      hence thesis by A1, A2, Th33;

    end;

    registration

      cluster ( TOP-REAL 3) -> up-3-dimensional;

      coherence

      proof

        take u = |[1, 0 , 0 ]|, v = |[ 0 , 1, 0 ]|, w = |[ 0 , 0 , 1]|;

        let a,b,c be Real such that

         A1: (((a * u) + (b * v)) + (c * w)) = ( 0. ( TOP-REAL 3));

        

         A2: ( |[a, b, c]| `1 ) = a & ( |[a, b, c]| `2 ) = b & ( |[a, b, c]| `3 ) = c by EUCLID_5: 2;

        

         A3: (c * w) = |[(c * 0 ), (c * 0 ), (c * 1)]| by EUCLID_5: 8;

        (a * u) = |[(a * 1), (a * 0 ), (a * 0 )]| & (b * v) = |[(b * 0 ), (b * 1), (b * 0 )]| by EUCLID_5: 8;

        

        then (((a * u) + (b * v)) + (c * w)) = ( |[(a + 0 ), ( 0 + b), ( 0 + 0 )]| + (c * w)) by EUCLID_5: 6

        .= |[(a + 0 ), (b + 0 ), ( 0 + c)]| by A3, EUCLID_5: 6;

        hence thesis by A1, A2, EUCLID_5: 2, EUCLID_5: 4;

      end;

    end

    theorem :: PASCAL:35

    

     Th35: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) & {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) & (P1,P2,P3) are_collinear & (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration implies (P7,P8,P9) are_collinear

    proof

      assume that

       A1: not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) and

       A2: {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) and

       A3: (P1,P2,P3) are_collinear and

       A4: (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration ;

       not (P1,P4,P5) are_collinear by A4, COLLSP: 8;

      then

      consider N be invertible Matrix of 3, F_Real such that

       A5: (( homography N) . P1) = Dir100 and

       A6: (( homography N) . P2) = Dir010 and

       A7: (( homography N) . P4) = Dir001 and

       A8: (( homography N) . P5) = Dir111 by A4, ANPROJ_9: 30;

      consider u3 be Point of ( TOP-REAL 3) such that

       A9: u3 is non zero and

       A10: (( homography N) . P3) = ( Dir u3) by ANPROJ_1: 26;

      reconsider p31 = (u3 . 1), p32 = (u3 . 2), p33 = (u3 . 3) as Real;

      

       A11: (u3 `1 ) = (u3 . 1) & (u3 `2 ) = (u3 . 2) & (u3 `3 ) = (u3 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A12: (( homography N) . P3) = ( Dir |[p31, p32, p33]|) by A10, EUCLID_5: 3;

      consider u6 be Point of ( TOP-REAL 3) such that

       A13: u6 is non zero and

       A14: (( homography N) . P6) = ( Dir u6) by ANPROJ_1: 26;

      reconsider p61 = (u6 . 1), p62 = (u6 . 2), p63 = (u6 . 3) as Real;

      

       A15: (u6 `1 ) = (u6 . 1) & (u6 `2 ) = (u6 . 2) & (u6 `3 ) = (u6 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      then

       A16: (( homography N) . P6) = ( Dir |[p61, p62, p63]|) by A14, EUCLID_5: 3;

      

       A17: P1 in {P1, P2, P3, P4, P5, P6} & P2 in {P1, P2, P3, P4, P5, P6} & P3 in {P1, P2, P3, P4, P5, P6} & P4 in {P1, P2, P3, P4, P5, P6} & P5 in {P1, P2, P3, P4, P5, P6} & P6 in {P1, P2, P3, P4, P5, P6} by ENUMSET1:def 4;

      consider a2,b2,c2,d2,e2,f2 be Real such that

       A18: not (a2 = 0 & b2 = 0 & c2 = 0 & d2 = 0 & e2 = 0 & f2 = 0 ) and

       A19: (( homography N) . P1) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A20: (( homography N) . P2) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A21: (( homography N) . P3) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A22: (( homography N) . P4) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A23: (( homography N) . P5) in ( conic (a2,b2,c2,d2,e2,f2)) and

       A24: (( homography N) . P6) in ( conic (a2,b2,c2,d2,e2,f2)) by A17, A2, A1, Th17;

      consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

       A25: ( Dir |[1, 0 , 0 ]|) = P and

       A26: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A5, A19;

      

       A27: ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 0 , 0 ]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 1, 0 ]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 0 , 1]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 1, 1]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[p31, p32, p33]|)) = 0 & ( qfconic (a2,b2,c2,d2,e2,f2, |[p61, p62, p63]|)) = 0

      proof

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 0 , 0 ]|)) = 0 by A25, A26, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A28: ( Dir |[ 0 , 1, 0 ]|) = P and

         A29: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A6, A20;

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 1, 0 ]|)) = 0 by A28, A29, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A30: ( Dir |[ 0 , 0 , 1]|) = P and

         A31: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A7, A22;

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[ 0 , 0 , 1]|)) = 0 by A30, A31, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A32: ( Dir |[1, 1, 1]|) = P and

         A33: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A8, A23;

        thus ( qfconic (a2,b2,c2,d2,e2,f2, |[1, 1, 1]|)) = 0 by A32, A33, ANPROJ_9: 10;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A34: ( Dir |[p31, p32, p33]|) = P and

         A35: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A12, A21;

         |[p31, p32, p33]| is non zero & ( Dir |[p31, p32, p33]|) = P by A34, A9, A11, EUCLID_5: 3;

        hence ( qfconic (a2,b2,c2,d2,e2,f2, |[p31, p32, p33]|)) = 0 by A35;

        consider P be Point of ( ProjectiveSpace ( TOP-REAL 3)) such that

         A36: ( Dir |[p61, p62, p63]|) = P and

         A37: for u be Element of ( TOP-REAL 3) st u is non zero & P = ( Dir u) holds ( qfconic (a2,b2,c2,d2,e2,f2,u)) = 0 by A16, A24;

         |[p61, p62, p63]| is non zero & ( Dir |[p61, p62, p63]|) = P by A36, A15, EUCLID_5: 3, A13;

        hence ( qfconic (a2,b2,c2,d2,e2,f2, |[p61, p62, p63]|)) = 0 by A37;

      end;

      reconsider a2f = a2, b2f = b2, c2f = c2, d2f = d2, e2f = e2, f2f = f2 as Element of F_Real by XREAL_0:def 1;

      ( qfconic (a2f,b2f,c2f,d2f,e2,f2f, |[1, 0 , 0 ]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[ 0 , 1, 0 ]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[ 0 , 0 , 1]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[1, 1, 1]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[p31, p32, p33]|)) = 0 & ( qfconic (a2f,b2f,c2f,d2f,e2f,f2f, |[p61, p62, p63]|)) = 0 by A27;

      then

       A38: a2f = 0 & b2f = 0 & c2f = 0 by Th18;

      then

       A39: a2f = 0 & b2f = 0 & c2f = 0 & ((d2f + e2f) + f2f) = 0 by A27, Th18;

      reconsider r1 = d2, r2 = f2 as Real;

       |[1, 0 , 0 ]| = <*1, 0 , 0 *> & <* 0 , 1, 0 *> = |[ 0 , 1, 0 ]| & <* 0 , 0 , 1*> = |[ 0 , 0 , 1]| & <*1, 1, 1*> = |[1, 1, 1]| & <*p31, p32, p33*> = |[p31, p32, p33]| & <*p61, p62, p63*> = |[p61, p62, p63]|;

      then

      reconsider p1 = <*1, 0 , 0 *>, p2 = <* 0 , 1, 0 *>, p4 = <* 0 , 0 , 1*>, p5 = <*1, 1, 1*>, p3 = <*p31, p32, p33*>, p6 = <*p61, p62, p63*> as Point of ( TOP-REAL 3);

      

       A42: u3 = |[p31, p32, p33]| by EUCLID_5: 3, A11;

      

       A43: u6 = |[p61, p62, p63]| by A15, EUCLID_5: 3;

      

       A44: (r1 <> 0 or r2 <> 0 ) & ( qfconic ( 0 , 0 , 0 ,r1,( - (r1 + r2)),r2,p3)) = 0 & ( qfconic ( 0 , 0 , 0 ,r1,( - (r1 + r2)),r2,p6)) = 0 by A39, A27, A18;

      

       A45: (p1 `1 ) = 1 & (p1 `2 ) = 0 & (p1 `3 ) = 0 & (p2 `1 ) = 0 & (p2 `2 ) = 1 & (p2 `3 ) = 0 & (p3 `1 ) = p31 & (p3 `2 ) = p32 & (p3 `3 ) = p33 by EUCLID_5: 2;

      

       A46: (p3 `1 ) = (p3 . 1) & (p3 `2 ) = (p3 . 2) & (p3 `3 ) = (p3 . 3) by EUCLID_5:def 1, EUCLID_5:def 2, EUCLID_5:def 3;

      

       A47: (( homography N) . P1) = ( Dir p1) & (( homography N) . P2) = ( Dir p2) & (( homography N) . P3) = ( Dir p3) by A5, A6, A11, A10, EUCLID_5: 3;

       |{p1, p2, p3}| = 0

      proof

        consider u,v,w be Element of ( TOP-REAL 3) such that

         A48: (( homography N) . P1) = ( Dir u) and

         A49: (( homography N) . P2) = ( Dir v) and

         A50: (( homography N) . P3) = ( Dir w) and

         A51: u is non zero and

         A52: v is non zero and

         A53: w is non zero and

         A54: (u,v,w) are_LinDep by A3, ANPROJ_8: 102, ANPROJ_2: 23;

        

         A55: [( Dir u), ( Dir v), ( Dir w)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by A51, A52, A53, A54, ANPROJ_1: 25;

        (p1,p2,p3) are_LinDep by A5, A6, A10, ANPROJ_9: 10, A42, A9, A48, A49, A50, A55, ANPROJ_1: 25;

        hence thesis by ANPROJ_8: 43;

      end;

      

      then

       A56: 0 = (((((((1 * (p2 `2 )) * (p3 `3 )) - (( 0 * (p2 `2 )) * (p3 `1 ))) - ((1 * (p2 `3 )) * (p3 `2 ))) + (( 0 * (p2 `3 )) * (p3 `1 ))) - (( 0 * (p2 `1 )) * (p3 `3 ))) + (( 0 * (p2 `1 )) * (p3 `2 ))) by A45, ANPROJ_8: 27

      .= (p3 `3 ) by A45;

      

       A57: p31 <> 0 & p32 <> 0

      proof

        assume p31 = 0 or p32 = 0 ;

        per cases ;

          suppose p31 = 0 ;

          

          then

           A58: p3 = |[(p32 * 0 ), (p32 * 1), (p32 * 0 )]| by A56, EUCLID_5: 2

          .= (p32 * |[ 0 , 1, 0 ]|) by EUCLID_5: 8;

          now

            p32 <> 0

            proof

              assume p32 = 0 ;

              

              then p3 = |[( 0 * 0 ), ( 0 * 1), ( 0 * 0 )]| by A58, EUCLID_5: 8

              .= ( 0. ( TOP-REAL 3)) by EUCLID_5: 4;

              hence thesis by A11, EUCLID_5: 3, A9;

            end;

            hence are_Prop (p3, |[ 0 , 1, 0 ]|) by A58, ANPROJ_1: 1;

            thus p3 is non zero by A11, EUCLID_5: 3, A9;

            thus |[ 0 , 1, 0 ]| is non zero by ANPROJ_9: 11;

          end;

          then (( homography N) . P3) = (( homography N) . P2) by A47, ANPROJ_1: 22;

          then P3 = P2 by ANPROJ_9: 16;

          hence contradiction by A4, ANPROJ_2:def 7;

        end;

          suppose p32 = 0 ;

          

          then

           A59: p3 = |[(p31 * 1), (p31 * 0 ), (p31 * 0 )]| by A56, EUCLID_5: 2

          .= (p31 * |[1, 0 , 0 ]|) by EUCLID_5: 8;

          now

            p31 <> 0

            proof

              assume p31 = 0 ;

              

              then p3 = |[( 0 * 1), ( 0 * 0 ), ( 0 * 0 )]| by A59, EUCLID_5: 8

              .= ( 0. ( TOP-REAL 3)) by EUCLID_5: 4;

              hence thesis by EUCLID_5: 3, A11, A9;

            end;

            hence are_Prop (p3, |[1, 0 , 0 ]|) by A59, ANPROJ_1: 1;

            thus p3 is non zero by EUCLID_5: 3, A11, A9;

            thus |[1, 0 , 0 ]| is non zero by ANPROJ_9: 11;

          end;

          then ( Dir p3) = Dir100 by ANPROJ_1: 22;

          then P3 = P1 by A47, ANPROJ_9: 16;

          hence contradiction by ANPROJ_2:def 7, A4;

        end;

      end;

      now

        

         A60: r1 = 0

        proof

          assume r1 <> 0 ;

          then (r1 * p31) <> 0 by A57, XCMPLX_1: 6;

          hence contradiction by A57, XCMPLX_1: 6, A38, A27, A46, A56, A45;

        end;

        hence ((r2 * (p6 . 3)) * ((p6 . 1) - (p6 . 2))) = 0 by A44;

        thus r2 <> 0

        proof

          assume

           A61: r2 = 0 ;

          

           A62: a2f = 0 & b2f = 0 & c2f = 0 & ((d2f + e2f) + f2f) = 0 by A38, A27, Th18;

          thus thesis by A18, A62, A60, A61;

        end;

      end;

      then r2 <> 0 & ((r2 * (p6 . 3)) = 0 or ((p6 . 1) - (p6 . 2)) = 0 ) by XCMPLX_1: 6;

      per cases by XCMPLX_1: 6;

        suppose (p6 . 3) = 0 ;

        then

         A63: (p6 `3 ) = 0 by EUCLID_5:def 3;

        

         A64: p6 = |[(p61 + 0 ), ( 0 + p62), ( 0 + 0 )]| by A63, EUCLID_5: 2

        .= ( |[(p61 * 1), (p61 * 0 ), (p61 * 0 )]| + |[(p62 * 0 ), (p62 * 1), (p62 * 0 )]|) by EUCLID_5: 6

        .= ((p61 * |[1, 0 , 0 ]|) + |[(p62 * 0 ), (p62 * 1), (p62 * 0 )]|) by EUCLID_5: 8

        .= ((p61 * |[1, 0 , 0 ]|) + (p62 * |[ 0 , 1, 0 ]|)) by EUCLID_5: 8;

        per cases ;

          suppose p61 = 0 & p62 = 0 ;

          then p6 = ( 0. ( TOP-REAL 3)) by A63, EUCLID_5: 2, EUCLID_5: 4;

          hence thesis by A15, EUCLID_5: 3, A13;

        end;

          suppose

           A65: p61 <> 0 & p62 = 0 ;

          now

            p6 = |[(p61 * 1), (p61 * 0 ), (p61 * 0 )]| by A63, EUCLID_5: 2, A65

            .= (p61 * |[1, 0 , 0 ]|) by EUCLID_5: 8;

            hence are_Prop (p6, |[1, 0 , 0 ]|) by A65, ANPROJ_1: 1;

            thus p6 is non zero by A15, EUCLID_5: 3, A13;

            thus |[1, 0 , 0 ]| is non zero by ANPROJ_9: 11;

          end;

          then ( Dir p6) = Dir100 by ANPROJ_1: 22;

          then P1 = P6 by ANPROJ_9: 16, A5, A14, A43;

          hence thesis by A4, ANPROJ_2:def 7;

        end;

          suppose

           A66: p61 = 0 & p62 <> 0 ;

          now

            p6 = |[(p62 * 0 ), (p62 * 1), (p62 * 0 )]| by A63, EUCLID_5: 2, A66

            .= (p62 * |[ 0 , 1, 0 ]|) by EUCLID_5: 8;

            hence are_Prop (p6, |[ 0 , 1, 0 ]|) by A66, ANPROJ_1: 1;

            thus p6 is non zero by A15, EUCLID_5: 3, A13;

            thus |[ 0 , 1, 0 ]| is non zero by ANPROJ_9: 11;

          end;

          then ( Dir p6) = Dir010 by ANPROJ_1: 22;

          then P2 = P6 by ANPROJ_9: 16, A6, A14, A43;

          hence thesis by A4, ANPROJ_2:def 7;

        end;

          suppose p61 <> 0 & p62 <> 0 ;

          now

            now

              thus p6 = ((p61 * |[1, 0 , 0 ]|) + (p62 * |[ 0 , 1, 0 ]|)) by A64;

              thus |[1, 0 , 0 ]| is non zero by ANPROJ_9: 11;

              thus |[ 0 , 1, 0 ]| is non zero by ANPROJ_9: 11;

              thus not are_Prop ( |[1, 0 , 0 ]|, |[ 0 , 1, 0 ]|)

              proof

                assume are_Prop ( |[1, 0 , 0 ]|, |[ 0 , 1, 0 ]|);

                then

                consider a be Real such that a <> 0 and

                 A67: |[1, 0 , 0 ]| = (a * |[ 0 , 1, 0 ]|) by ANPROJ_1: 1;

                 |[1, 0 , 0 ]| = |[(a * 0 ), (a * 1), (a * 0 )]| by A67, EUCLID_5: 8

                .= |[ 0 , a, 0 ]|;

                hence thesis by FINSEQ_1: 78;

              end;

            end;

            hence ( |[1, 0 , 0 ]|, |[ 0 , 1, 0 ]|,p6) are_LinDep by ANPROJ_1: 6;

            thus |[1, 0 , 0 ]| is non zero by ANPROJ_9: 11;

            thus |[ 0 , 1, 0 ]| is non zero by ANPROJ_9: 11;

            thus p6 is non zero by A15, EUCLID_5: 3, A13;

          end;

          then [ Dir100 , Dir010 , ( Dir p6)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by ANPROJ_1: 25;

          hence thesis by A4, A5, A6, A14, A43, COLLSP:def 2, ANPROJ_8: 102;

        end;

      end;

        suppose

         A68: (p6 . 1) = (p6 . 2);

        

         A69: p61 = (p6 `1 ) by EUCLID_5: 2

        .= (p6 . 2) by A68, EUCLID_5:def 1

        .= (p6 `2 ) by EUCLID_5:def 2

        .= p62 by EUCLID_5: 2;

        now

          thus p4 is non zero by ANPROJ_9: 11;

          thus p5 is non zero by ANPROJ_9: 11;

          thus p6 is non zero by A13, A15, EUCLID_5: 3;

           |{p4, p5, p6}| = 0

          proof

            (p6 `1 ) = p61 & (p6 `2 ) = p61 & (p4 `1 ) = 0 & (p4 `2 ) = 0 & (p4 `3 ) = 1 & (p5 `1 ) = 1 & (p5 `2 ) = 1 & (p5 `3 ) = 1 & |{p4, p5, p6}| = ((((((((p4 `1 ) * (p5 `2 )) * (p6 `3 )) - (((p4 `3 ) * (p5 `2 )) * (p6 `1 ))) - (((p4 `1 ) * (p5 `3 )) * (p6 `2 ))) + (((p4 `2 ) * (p5 `3 )) * (p6 `1 ))) - (((p4 `2 ) * (p5 `1 )) * (p6 `3 ))) + (((p4 `3 ) * (p5 `1 )) * (p6 `2 ))) by EUCLID_5: 2, A69, ANPROJ_8: 27;

            hence thesis;

          end;

          hence ( |[ 0 , 0 , 1]|, |[1, 1, 1]|,p6) are_LinDep by ANPROJ_8: 43;

        end;

        then

         A70: [ Dir001 , Dir111 , ( Dir p6)] in the Collinearity of ( ProjectiveSpace ( TOP-REAL 3)) by ANPROJ_1: 25;

        reconsider p1 = P1, p2 = P2, p3 = P3, q1 = P4, q2 = P5, q3 = P6, r1 = P7, r2 = P8, r3 = P9 as Element of ( ProjectiveSpace ( TOP-REAL 3));

        p2 <> p3 & p1 <> p3 & q2 <> q3 & q1 <> q2 & q1 <> q3 & not (p1,p2,q1) are_collinear & (p1,p2,p3) are_collinear & (q1,q2,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 by COLLSP: 2, A3, A4, A70, A7, A8, A14, A43, COLLSP:def 2, ANPROJ_2: 24, ANPROJ_8: 102;

        hence thesis by ANPROJ_8: 57, HESSENBE: 16;

      end;

    end;

    ::$Notion-Name

    theorem :: PASCAL:36

     not (a = 0 & b = 0 & c = 0 & d = 0 & e = 0 & f = 0 ) & {P1, P2, P3, P4, P5, P6} c= ( conic (a,b,c,d,e,f)) & (P1,P2,P3,P4,P5,P6,P7,P8,P9) are_in_Pascal_configuration implies (P7,P8,P9) are_collinear

    proof

      per cases ;

        suppose (P1,P2,P3) are_collinear ;

        hence thesis by Th35;

      end;

        suppose not (P1,P2,P3) are_collinear ;

        hence thesis by Th34;

      end;

    end;