:: INCPROJ semantic presentation  Show TPTP formulae Show IDV graph for whole article:: Showing IDV graph ... (Click the Palm Trees again to close it)

definition
let CPS be proper CollSp;
:: original: LINE
redefine mode LINE of CPS -> Subset of CPS;
coherence
for b1 being LINE of CPS holds b1 is Subset of CPS
proof end;
end;

definition
let CPS be proper CollSp;
func ProjectiveLines CPS -> set equals :: INCPROJ:def 1
{ B where B is Subset of CPS : B is LINE of CPS } ;
coherence
{ B where B is Subset of CPS : B is LINE of CPS } is set
;
end;

:: deftheorem defines ProjectiveLines INCPROJ:def 1 :
for CPS being proper CollSp holds ProjectiveLines CPS = { B where B is Subset of CPS : B is LINE of CPS } ;

registration
let CPS be proper CollSp;
cluster ProjectiveLines CPS -> non empty ;
coherence
not ProjectiveLines CPS is empty
proof end;
end;

theorem :: INCPROJ:1  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem Th2: :: INCPROJ:2  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for x being set holds
( x is LINE of CPS iff x is Element of ProjectiveLines CPS )
proof end;

definition
let CPS be proper CollSp;
func Proj_Inc CPS -> Relation of the carrier of CPS, ProjectiveLines CPS means :Def2: :: INCPROJ:def 2
for x, y being set holds
( [x,y] in it iff ( x in the carrier of CPS & y in ProjectiveLines CPS & ex Y being set st
( y = Y & x in Y ) ) );
existence
ex b1 being Relation of the carrier of CPS, ProjectiveLines CPS st
for x, y being set holds
( [x,y] in b1 iff ( x in the carrier of CPS & y in ProjectiveLines CPS & ex Y being set st
( y = Y & x in Y ) ) )
proof end;
uniqueness
for b1, b2 being Relation of the carrier of CPS, ProjectiveLines CPS st ( for x, y being set holds
( [x,y] in b1 iff ( x in the carrier of CPS & y in ProjectiveLines CPS & ex Y being set st
( y = Y & x in Y ) ) ) ) & ( for x, y being set holds
( [x,y] in b2 iff ( x in the carrier of CPS & y in ProjectiveLines CPS & ex Y being set st
( y = Y & x in Y ) ) ) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def2 defines Proj_Inc INCPROJ:def 2 :
for CPS being proper CollSp
for b2 being Relation of the carrier of CPS, ProjectiveLines CPS holds
( b2 = Proj_Inc CPS iff for x, y being set holds
( [x,y] in b2 iff ( x in the carrier of CPS & y in ProjectiveLines CPS & ex Y being set st
( y = Y & x in Y ) ) ) );

definition
let CPS be proper CollSp;
func IncProjSp_of CPS -> IncProjStr equals :: INCPROJ:def 3
IncProjStr(# the carrier of CPS,(ProjectiveLines CPS),(Proj_Inc CPS) #);
coherence
IncProjStr(# the carrier of CPS,(ProjectiveLines CPS),(Proj_Inc CPS) #) is IncProjStr
;
end;

:: deftheorem defines IncProjSp_of INCPROJ:def 3 :
for CPS being proper CollSp holds IncProjSp_of CPS = IncProjStr(# the carrier of CPS,(ProjectiveLines CPS),(Proj_Inc CPS) #);

registration
let CPS be proper CollSp;
cluster IncProjSp_of CPS -> strict ;
coherence
IncProjSp_of CPS is strict
;
end;

theorem :: INCPROJ:3  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem :: INCPROJ:4  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp holds
( the Points of (IncProjSp_of CPS) = the carrier of CPS & the Lines of (IncProjSp_of CPS) = ProjectiveLines CPS & the Inc of (IncProjSp_of CPS) = Proj_Inc CPS ) ;

theorem :: INCPROJ:5  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for x being set holds
( x is Point of CPS iff x is POINT of (IncProjSp_of CPS) ) ;

theorem Th6: :: INCPROJ:6  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for x being set holds
( x is LINE of CPS iff x is LINE of (IncProjSp_of CPS) ) by Th2;

theorem :: INCPROJ:7  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
canceled;

theorem Th8: :: INCPROJ:8  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for s being POINT of (IncProjSp_of CPS)
for S being LINE of (IncProjSp_of CPS) holds
( s on S iff [s,S] in Proj_Inc CPS ) by INCSP_1:def 1;

theorem Th9: :: INCPROJ:9  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for p being POINT of (IncProjSp_of CPS)
for P being LINE of (IncProjSp_of CPS)
for p' being Point of CPS
for P' being LINE of CPS st p = p' & P = P' holds
( p on P iff p' in P' )
proof end;

theorem Th10: :: INCPROJ:10  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp ex a', b', c' being Point of CPS st
( a' <> b' & b' <> c' & c' <> a' )
proof end;

theorem Th11: :: INCPROJ:11  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for a' being Point of CPS ex b' being Point of CPS st a' <> b'
proof end;

theorem Th12: :: INCPROJ:12  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for p, q being POINT of (IncProjSp_of CPS)
for P, Q being LINE of (IncProjSp_of CPS) st p on P & q on P & p on Q & q on Q & not p = q holds
P = Q
proof end;

theorem Th13: :: INCPROJ:13  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for p, q being POINT of (IncProjSp_of CPS) ex P being LINE of (IncProjSp_of CPS) st
( p on P & q on P )
proof end;

theorem Th14: :: INCPROJ:14  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp
for a, b, c being POINT of (IncProjSp_of CPS)
for a', b', c' being Point of CPS st a = a' & b = b' & c = c' holds
( a',b',c' is_collinear iff ex P being LINE of (IncProjSp_of CPS) st
( a on P & b on P & c on P ) )
proof end;

theorem Th15: :: INCPROJ:15  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being proper CollSp holds
not for p being POINT of (IncProjSp_of CPS)
for P being LINE of (IncProjSp_of CPS) holds p on P
proof end;

theorem Th16: :: INCPROJ:16  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace
for P being LINE of (IncProjSp_of CPS) ex a, b, c being POINT of (IncProjSp_of CPS) st
( a <> b & b <> c & c <> a & a on P & b on P & c on P )
proof end;

theorem Th17: :: INCPROJ:17  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace
for a, b, c, d, p being POINT of (IncProjSp_of CPS)
for M, N, P, Q being LINE of (IncProjSp_of CPS) st a on M & b on M & c on N & d on N & p on M & p on N & a on P & c on P & b on Q & d on Q & not p on P & not p on Q & M <> N holds
ex q being POINT of (IncProjSp_of CPS) st
( q on P & q on Q )
proof end;

theorem Th18: :: INCPROJ:18  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace st ( for a', b', c', d' being Point of CPS ex p' being Point of CPS st
( a',b',p' is_collinear & c',d',p' is_collinear ) ) holds
for M, N being LINE of (IncProjSp_of CPS) ex q being POINT of (IncProjSp_of CPS) st
( q on M & q on N )
proof end;

theorem Th19: :: INCPROJ:19  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace st ex p, p1, r, r1 being Point of CPS st
for s being Point of CPS holds
( not p,p1,s is_collinear or not r,r1,s is_collinear ) holds
ex M, N being LINE of (IncProjSp_of CPS) st
for q being POINT of (IncProjSp_of CPS) holds
( not q on M or not q on N )
proof end;

theorem Th20: :: INCPROJ:20  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace st ( for p, p1, q, q1, r2 being Point of CPS ex r, r1 being Point of CPS st
( p,q,r is_collinear & p1,q1,r1 is_collinear & r2,r,r1 is_collinear ) ) holds
for a being POINT of (IncProjSp_of CPS)
for M, N being LINE of (IncProjSp_of CPS) ex b, c being POINT of (IncProjSp_of CPS) ex S being LINE of (IncProjSp_of CPS) st
( a on S & b on S & c on S & b on M & c on N )
proof end;

definition
let x, y, z be set ;
canceled;
pred x,y,z are_mutually_different means :Def5: :: INCPROJ:def 5
( x <> y & y <> z & z <> x );
let u be set ;
pred x,y,z,u are_mutually_different means :Def6: :: INCPROJ:def 6
( x <> y & y <> z & z <> x & u <> x & u <> y & u <> z );
end;

:: deftheorem INCPROJ:def 4 :
canceled;

:: deftheorem Def5 defines are_mutually_different INCPROJ:def 5 :
for x, y, z being set holds
( x,y,z are_mutually_different iff ( x <> y & y <> z & z <> x ) );

:: deftheorem Def6 defines are_mutually_different INCPROJ:def 6 :
for x, y, z, u being set holds
( x,y,z,u are_mutually_different iff ( x <> y & y <> z & z <> x & u <> x & u <> y & u <> z ) );

definition
let CS be IncProjStr ;
let a, b be POINT of CS;
let M be LINE of CS;
pred a,b on M means :Def7: :: INCPROJ:def 7
( a on M & b on M );
let c be POINT of CS;
pred a,b,c on M means :Def8: :: INCPROJ:def 8
( a on M & b on M & c on M );
end;

:: deftheorem Def7 defines on INCPROJ:def 7 :
for CS being IncProjStr
for a, b being POINT of CS
for M being LINE of CS holds
( a,b on M iff ( a on M & b on M ) );

:: deftheorem Def8 defines on INCPROJ:def 8 :
for CS being IncProjStr
for a, b being POINT of CS
for M being LINE of CS
for c being POINT of CS holds
( a,b,c on M iff ( a on M & b on M & c on M ) );

theorem Th21: :: INCPROJ:21  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace st ( for p1, r2, q, r1, q1, p, r being Point of CPS st p1,r2,q is_collinear & r1,q1,q is_collinear & p1,r1,p is_collinear & r2,q1,p is_collinear & p1,q1,r is_collinear & r2,r1,r is_collinear & p,q,r is_collinear & not p1,r2,q1 is_collinear & not p1,r2,r1 is_collinear & not p1,r1,q1 is_collinear holds
r2,r1,q1 is_collinear ) holds
for p, q, r, s, a, b, c being POINT of (IncProjSp_of CPS)
for L, Q, R, S, A, B, C being LINE of (IncProjSp_of CPS) st not q on L & not r on L & not p on Q & not s on Q & not p on R & not r on R & not q on S & not s on S & a,p,s on L & a,q,r on Q & b,q,s on R & b,p,r on S & c,p,q on A & c,r,s on B & a,b on C holds
not c on C
proof end;

theorem Th22: :: INCPROJ:22  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace st ( for o, p1, p2, p3, q1, q2, q3, r1, r2, r3 being Point of CPS st o <> q1 & p1 <> q1 & o <> q2 & p2 <> q2 & o <> q3 & p3 <> q3 & not o,p1,p2 is_collinear & not o,p1,p3 is_collinear & not o,p2,p3 is_collinear & p1,p2,r3 is_collinear & q1,q2,r3 is_collinear & p2,p3,r1 is_collinear & q2,q3,r1 is_collinear & p1,p3,r2 is_collinear & q1,q3,r2 is_collinear & o,p1,q1 is_collinear & o,p2,q2 is_collinear & o,p3,q3 is_collinear holds
r1,r2,r3 is_collinear ) holds
for o, b1, a1, b2, a2, b3, a3, r, s, t being POINT of (IncProjSp_of CPS)
for C1, C2, C3, A1, A2, A3, B1, B2, B3 being LINE of (IncProjSp_of CPS) st o,b1,a1 on C1 & o,a2,b2 on C2 & o,a3,b3 on C3 & a3,a2,t on A1 & a3,r,a1 on A2 & a2,s,a1 on A3 & t,b2,b3 on B1 & b1,r,b3 on B2 & b1,s,b2 on B3 & C1,C2,C3 are_mutually_different & o <> a1 & o <> a2 & o <> a3 & o <> b1 & o <> b2 & o <> b3 & a1 <> b1 & a2 <> b2 & a3 <> b3 holds
ex O being LINE of (IncProjSp_of CPS) st r,s,t on O
proof end;

theorem Th23: :: INCPROJ:23  Show TPTP formulae Show IDV graph:: Showing IDV graph ... (Click the Palm Tree again to close it) Show TPTP problem
for CPS being CollProjectiveSpace st ( for o, p1, p2, p3, q1, q2, q3, r1, r2, r3 being Point of CPS st o <> p2 & o <> p3 & p2 <> p3 & p1 <> p2 & p1 <> p3 & o <> q2 & o <> q3 & q2 <> q3 & q1 <> q2 & q1 <> q3 & not o,p1,q1 is_collinear & o,p1,p2 is_collinear & o,p1,p3 is_collinear & o,q1,q2 is_collinear & o,q1,q3 is_collinear & p1,q2,r3 is_collinear & q1,p2,r3 is_collinear & p1,q3,r2 is_collinear & p3,q1,r2 is_collinear & p2,q3,r1 is_collinear & p3,q2,r1 is_collinear holds
r1,r2,r3 is_collinear ) holds
for o, a1, a2, a3, b1, b2, b3, c1, c2, c3 being POINT of (IncProjSp_of CPS)
for A1, A2, A3, B1, B2, B3, C1, C2, C3 being LINE of (IncProjSp_of CPS) st o,a1,a2,a3 are_mutually_different & o,b1,b2,b3 are_mutually_different & A3 <> B3 & o on A3 & o on B3 & a2,b3,c1 on A1 & a3,b1,c2 on B1 & a1,b2,c3 on C1 & a1,b3,c2 on A2 & a3,b2,c1 on B2 & a2,b1,c3 on C2 & b1,b2,b3 on A3 & a1,a2,a3 on B3 & c1,c2 on C3 holds
c3 on C3
proof end;

definition
let IT be IncProjStr ;
attr IT is partial means :Def9: :: INCPROJ:def 9
for p, q being POINT of IT
for P, Q being LINE of IT st p on P & q on P & p on Q & q on Q & not p = q holds
P = Q;
attr IT is linear means :Def10: :: INCPROJ:def 10
for p, q being POINT of IT ex P being LINE of IT st
( p on P & q on P );
attr IT is up-2-dimensional means :Def11: :: INCPROJ:def 11
not for p being POINT of IT
for P being LINE of IT holds p on P;
attr IT is up-3-rank means :Def12: :: INCPROJ:def 12
for P being LINE of IT ex a, b, c being POINT of IT st
( a <> b & b <> c & c <> a & a on P & b on P & c on P );
attr IT is Vebleian means :Def13: :: INCPROJ:def 13
for a, b, c, d, p, q being POINT of IT
for M, N, P, Q being LINE of IT st a on M & b on M & c on N & d on N & p on M & p on N & a on P & c on P & b on Q & d on Q & not p on P & not p on Q & M <> N holds
ex q being POINT of IT st
( q on P & q on Q );
end;

:: deftheorem Def9 defines partial INCPROJ:def 9 :
for IT being IncProjStr holds
( IT is partial iff for p, q being POINT of IT
for P, Q being LINE of IT st p on P & q on P & p on Q & q on Q & not p = q holds
P = Q );

:: deftheorem Def10 defines linear INCPROJ:def 10 :
for IT being IncProjStr holds
( IT is linear iff for p, q being POINT of IT ex P being LINE of IT st
( p on P & q on P ) );

:: deftheorem Def11 defines up-2-dimensional INCPROJ:def 11 :
for IT being IncProjStr holds
( IT is up-2-dimensional iff not for p being POINT of IT
for P being LINE of IT holds p on P );

:: deftheorem Def12 defines up-3-rank INCPROJ:def 12 :
for IT being IncProjStr holds
( IT is up-3-rank iff for P being LINE of IT ex a, b, c being POINT of IT st
( a <> b & b <> c & c <> a & a on P & b on P & c on P ) );

:: deftheorem Def13 defines Vebleian INCPROJ:def 13 :
for IT being IncProjStr holds
( IT is Vebleian iff for a, b, c, d, p, q being POINT of IT
for M, N, P, Q being LINE of IT st a on M & b on M & c on N & d on N & p on M & p on N & a on P & c on P & b on Q & d on Q & not p on P & not p on Q & M <> N holds
ex q being POINT of IT st
( q on P & q on Q ) );

registration
let CPS be CollProjectiveSpace;
cluster IncProjSp_of CPS -> strict partial linear up-2-dimensional up-3-rank Vebleian ;
coherence
( IncProjSp_of CPS is partial & IncProjSp_of CPS is linear & IncProjSp_of CPS is up-2-dimensional & IncProjSp_of CPS is up-3-rank & IncProjSp_of CPS is Vebleian )
proof end;
end;

registration
cluster strict partial linear up-2-dimensional up-3-rank Vebleian IncProjStr ;
existence
ex b1 being IncProjStr st
( b1 is strict & b1 is partial & b1 is linear & b1 is up-2-dimensional & b1 is up-3-rank & b1 is Vebleian )
proof end;
end;

definition
mode IncProjSp is partial linear up-2-dimensional up-3-rank Vebleian IncProjStr ;
end;

registration
let CPS be CollProjectiveSpace;
cluster IncProjSp_of CPS -> strict partial linear up-2-dimensional up-3-rank Vebleian ;
coherence
( IncProjSp_of CPS is partial & IncProjSp_of CPS is linear & IncProjSp_of CPS is up-2-dimensional & IncProjSp_of CPS is up-3-rank & IncProjSp_of CPS is Vebleian )
;
end;

definition
let IT be IncProjSp;
attr IT is 2-dimensional means :Def14: :: INCPROJ:def 14
for M, N being LINE of IT ex q being POINT of IT st
( q on M & q on N );
end;

:: deftheorem Def14 defines 2-dimensional INCPROJ:def 14 :
for IT being IncProjSp holds
( IT is 2-dimensional iff for M, N being LINE of IT ex q being POINT of IT st
( q on M & q on N ) );

notation
let IT be IncProjSp;
antonym up-3-dimensional IT for 2-dimensional IT;
end;

definition
let IT be IncProjSp;
canceled;
attr IT is at_most-3-dimensional means :Def16: :: INCPROJ:def 16
for a being POINT of IT
for M, N being LINE of IT ex b, c being POINT of IT ex S being LINE of IT st
( a on S & b on S & c on S & b on M & c on N );
end;

:: deftheorem INCPROJ:def 15 :
canceled;

:: deftheorem Def16 defines at_most-3-dimensional INCPROJ:def 16 :
for IT being IncProjSp holds
( IT is at_most-3-dimensional iff for a being POINT of IT
for M, N being LINE of IT ex b, c being POINT of IT ex S being LINE of IT st
( a on S & b on S & c on S & b on M & c on N ) );

definition
let IT be IncProjSp;
attr IT is 3-dimensional means :: INCPROJ:def 17
( IT is at_most-3-dimensional & not IT is 2-dimensional );
end;

:: deftheorem defines 3-dimensional INCPROJ:def 17 :
for IT being IncProjSp holds
( IT is 3-dimensional iff ( IT is at_most-3-dimensional & not IT is 2-dimensional ) );

definition
let IT be IncProjSp;
attr IT is Fanoian means :Def18: :: INCPROJ:def 18
for p, q, r, s, a, b, c being POINT of IT
for L, Q, R, S, A, B, C being LINE of IT st not q on L & not r on L & not p on Q & not s on Q & not p on R & not r on R & not q on S & not s on S & a,p,s on L & a,q,r on Q & b,q,s on R & b,p,r on S & c,p,q on A & c,r,s on B & a,b on C holds
not c on C;
end;

:: deftheorem Def18 defines Fanoian INCPROJ:def 18 :
for IT being IncProjSp holds
( IT is Fanoian iff for p, q, r, s, a, b, c being POINT of IT
for L, Q, R, S, A, B, C being LINE of IT st not q on L & not r on L & not p on Q & not s on Q & not p on R & not r on R & not q on S & not s on S & a,p,s on L & a,q,r on Q & b,q,s on R & b,p,r on S & c,p,q on A & c,r,s on B & a,b on C holds
not c on C );

definition
let IT be IncProjSp;
attr IT is Desarguesian means :Def19: :: INCPROJ:def 19
for o, b1, a1, b2, a2, b3, a3, r, s, t being POINT of IT
for C1, C2, C3, A1, A2, A3, B1, B2, B3 being LINE of IT st o,b1,a1 on C1 & o,a2,b2 on C2 & o,a3,b3 on C3 & a3,a2,t on A1 & a3,r,a1 on A2 & a2,s,a1 on A3 & t,b2,b3 on B1 & b1,r,b3 on B2 & b1,s,b2 on B3 & C1,C2,C3 are_mutually_different & o <> a1 & o <> a2 & o <> a3 & o <> b1 & o <> b2 & o <> b3 & a1 <> b1 & a2 <> b2 & a3 <> b3 holds
ex O being LINE of IT st r,s,t on O;
end;

:: deftheorem Def19 defines Desarguesian INCPROJ:def 19 :
for IT being IncProjSp holds
( IT is Desarguesian iff for o, b1, a1, b2, a2, b3, a3, r, s, t being POINT of IT
for C1, C2, C3, A1, A2, A3, B1, B2, B3 being LINE of IT st o,b1,a1 on C1 & o,a2,b2 on C2 & o,a3,b3 on C3 & a3,a2,t on A1 & a3,r,a1 on A2 & a2,s,a1 on A3 & t,b2,b3 on B1 & b1,r,b3 on B2 & b1,s,b2 on B3 & C1,C2,C3 are_mutually_different & o <> a1 & o <> a2 & o <> a3 & o <> b1 & o <> b2 & o <> b3 & a1 <> b1 & a2 <> b2 & a3 <> b3 holds
ex O being LINE of IT st r,s,t on O );

definition
let IT be IncProjSp;
attr IT is Pappian means :Def20: :: INCPROJ:def 20
for o, a1, a2, a3, b1, b2, b3, c1, c2, c3 being POINT of IT
for A1, A2, A3, B1, B2, B3, C1, C2, C3 being LINE of IT st o,a1,a2,a3 are_mutually_different & o,b1,b2,b3 are_mutually_different & A3 <> B3 & o on A3 & o on B3 & a2,b3,c1 on A1 & a3,b1,c2 on B1 & a1,b2,c3 on C1 & a1,b3,c2 on A2 & a3,b2,c1 on B2 & a2,b1,c3 on C2 & b1,b2,b3 on A3 & a1,a2,a3 on B3 & c1,c2 on C3 holds
c3 on C3;
end;

:: deftheorem Def20 defines Pappian INCPROJ:def 20 :
for IT being IncProjSp holds
( IT is Pappian iff for o, a1, a2, a3, b1, b2, b3, c1, c2, c3 being POINT of IT
for A1, A2, A3, B1, B2, B3, C1, C2, C3 being LINE of IT st o,a1,a2,a3 are_mutually_different & o,b1,b2,b3 are_mutually_different & A3 <> B3 & o on A3 & o on B3 & a2,b3,c1 on A1 & a3,b1,c2 on B1 & a1,b2,c3 on C1 & a1,b3,c2 on A2 & a3,b2,c1 on B2 & a2,b1,c3 on C2 & b1,b2,b3 on A3 & a1,a2,a3 on B3 & c1,c2 on C3 holds
c3 on C3 );

registration
cluster up-3-dimensional at_most-3-dimensional Fanoian Desarguesian IncProjStr ;
existence
ex b1 being IncProjSp st
( b1 is Desarguesian & b1 is Fanoian & b1 is at_most-3-dimensional & not b1 is 2-dimensional )
proof end;
end;

registration
cluster up-3-dimensional at_most-3-dimensional Fanoian Pappian IncProjStr ;
existence
ex b1 being IncProjSp st
( b1 is Pappian & b1 is Fanoian & b1 is at_most-3-dimensional & not b1 is 2-dimensional )
proof end;
end;

registration
cluster 2-dimensional Fanoian Desarguesian IncProjStr ;
existence
ex b1 being IncProjSp st
( b1 is Desarguesian & b1 is Fanoian & b1 is 2-dimensional )
proof end;
end;

registration
cluster 2-dimensional Fanoian Pappian IncProjStr ;
existence
ex b1 being IncProjSp st
( b1 is Pappian & b1 is Fanoian & b1 is 2-dimensional )
proof end;
end;