let X be OrtAfPl; :: thesis: ( X is satisfying_PAP iff AffinStruct(# the U1 of X, the CONGR of X #) is Pappian )
A1: ( X is satisfying_PAP implies AffinStruct(# the U1 of X, the CONGR of X #) is Pappian )
proof
assume A2: X is satisfying_PAP ; :: thesis: AffinStruct(# the U1 of X, the CONGR of X #) is Pappian
now :: thesis: for M, N being Subset of AffinStruct(# the U1 of X, the CONGR of X #)
for o, a, b, c, a1, b1, c1 being Element of AffinStruct(# the U1 of X, the CONGR of X #) st M is being_line & N is being_line & M <> N & o in M & o in N & o <> a & o <> a1 & o <> b & o <> b1 & o <> c & o <> c1 & a in M & b in M & c in M & a1 in N & b1 in N & c1 in N & a,b1 // b,a1 & b,c1 // c,b1 holds
a,c1 // c,a1
let M, N be Subset of AffinStruct(# the U1 of X, the CONGR of X #); :: thesis: for o, a, b, c, a1, b1, c1 being Element of AffinStruct(# the U1 of X, the CONGR of X #) st M is being_line & N is being_line & M <> N & o in M & o in N & o <> a & o <> a1 & o <> b & o <> b1 & o <> c & o <> c1 & a in M & b in M & c in M & a1 in N & b1 in N & c1 in N & a,b1 // b,a1 & b,c1 // c,b1 holds
a,c1 // c,a1

let o, a, b, c, a1, b1, c1 be Element of AffinStruct(# the U1 of X, the CONGR of X #); :: thesis: ( M is being_line & N is being_line & M <> N & o in M & o in N & o <> a & o <> a1 & o <> b & o <> b1 & o <> c & o <> c1 & a in M & b in M & c in M & a1 in N & b1 in N & c1 in N & a,b1 // b,a1 & b,c1 // c,b1 implies a,c1 // c,a1 )
assume that
A3: M is being_line and
A4: N is being_line and
A5: M <> N and
A6: o in M and
A7: o in N and
A8: o <> a and
A9: o <> a1 and
A10: o <> b and
A11: o <> b1 and
A12: o <> c and
A13: o <> c1 and
A14: a in M and
A15: b in M and
A16: c in M and
A17: a1 in N and
A18: b1 in N and
A19: c1 in N and
A20: a,b1 // b,a1 and
A21: b,c1 // c,b1 ; :: thesis: a,c1 // c,a1
reconsider a9 = a, b9 = b, c9 = c, a19 = a1, b19 = b1, c19 = c1 as Element of X ;
reconsider M9 = M, N9 = N as Subset of X ;
A22: N9 is being_line by A4, ANALMETR:43;
A23: ( not c19 in M9 & not b9 in N9 )
proof
assume ( c19 in M9 or b9 in N9 ) ; :: thesis: contradiction
then A24: ( o,c1 // M or o,b // N ) by A3, A4, A6, A7, AFF_1:52;
A25: o,b // M by A3, A6, A15, AFF_1:52;
o,c1 // N by A4, A7, A19, AFF_1:52;
hence contradiction by A5, A6, A7, A10, A13, A24, A25, AFF_1:45, AFF_1:53; :: thesis: verum
end;
b,a1 // a,b1 by A20, AFF_1:4;
then A26: b9,a19 // a9,b19 by ANALMETR:36;
A27: b9,c19 // c9,b19 by A21, ANALMETR:36;
M9 is being_line by A3, ANALMETR:43;
then a9,c19 // c9,a19 by A2, A6, A7, A8, A9, A11, A12, A14, A15, A16, A17, A18, A19, A22, A26, A27, A23, CONMETR:def 2;
hence a,c1 // c,a1 by ANALMETR:36; :: thesis: verum
end;
hence AffinStruct(# the U1 of X, the CONGR of X #) is Pappian by AFF_2:def 2; :: thesis: verum
end;
( AffinStruct(# the U1 of X, the CONGR of X #) is Pappian implies X is satisfying_PAP )
proof
assume A28: AffinStruct(# the U1 of X, the CONGR of X #) is Pappian ; :: thesis: X is satisfying_PAP
now :: thesis: for o9, a19, a29, a39, b19, b29, b39 being Element of X
for M9, N9 being Subset of X st M9 is being_line & N9 is being_line & o9 in M9 & a19 in M9 & a29 in M9 & a39 in M9 & o9 in N9 & b19 in N9 & b29 in N9 & b39 in N9 & not b29 in M9 & not a39 in N9 & o9 <> a19 & o9 <> a29 & o9 <> a39 & o9 <> b19 & o9 <> b29 & o9 <> b39 & a39,b29 // a29,b19 & a39,b39 // a19,b19 holds
a19,b29 // a29,b39
let o9, a19, a29, a39, b19, b29, b39 be Element of X; :: thesis: for M9, N9 being Subset of X st M9 is being_line & N9 is being_line & o9 in M9 & a19 in M9 & a29 in M9 & a39 in M9 & o9 in N9 & b19 in N9 & b29 in N9 & b39 in N9 & not b29 in M9 & not a39 in N9 & o9 <> a19 & o9 <> a29 & o9 <> a39 & o9 <> b19 & o9 <> b29 & o9 <> b39 & a39,b29 // a29,b19 & a39,b39 // a19,b19 holds
a19,b29 // a29,b39

let M9, N9 be Subset of X; :: thesis: ( M9 is being_line & N9 is being_line & o9 in M9 & a19 in M9 & a29 in M9 & a39 in M9 & o9 in N9 & b19 in N9 & b29 in N9 & b39 in N9 & not b29 in M9 & not a39 in N9 & o9 <> a19 & o9 <> a29 & o9 <> a39 & o9 <> b19 & o9 <> b29 & o9 <> b39 & a39,b29 // a29,b19 & a39,b39 // a19,b19 implies a19,b29 // a29,b39 )
assume that
A29: M9 is being_line and
A30: N9 is being_line and
A31: o9 in M9 and
A32: a19 in M9 and
A33: a29 in M9 and
A34: a39 in M9 and
A35: o9 in N9 and
A36: b19 in N9 and
A37: b29 in N9 and
A38: b39 in N9 and
A39: not b29 in M9 and
A40: not a39 in N9 and
A41: o9 <> a19 and
A42: o9 <> a29 and
o9 <> a39 and
A43: o9 <> b19 and
o9 <> b29 and
A44: o9 <> b39 and
A45: a39,b29 // a29,b19 and
A46: a39,b39 // a19,b19 ; :: thesis: a19,b29 // a29,b39
reconsider a1 = a19, a2 = a29, a3 = a39, b1 = b19, b2 = b29, b3 = b39 as Element of AffinStruct(# the U1 of X, the CONGR of X #) ;
reconsider M = M9, N = N9 as Subset of AffinStruct(# the U1 of X, the CONGR of X #) ;
A47: N is being_line by A30, ANALMETR:43;
A48: M is being_line by A29, ANALMETR:43;
now :: thesis: ( M <> N implies a19,b29 // a29,b39 )
assume M <> N ; :: thesis: a19,b29 // a29,b39
a3,b3 // a1,b1 by A46, ANALMETR:36;
then A49: a1,b1 // a3,b3 by AFF_1:4;
a3,b2 // a2,b1 by A45, ANALMETR:36;
then a1,b2 // a2,b3 by A28, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A48, A47, A49, AFF_2:def 2;
hence a19,b29 // a29,b39 by ANALMETR:36; :: thesis: verum
end;
hence a19,b29 // a29,b39 by A37, A39; :: thesis: verum
end;
hence X is satisfying_PAP by CONMETR:def 2; :: thesis: verum
end;
hence ( X is satisfying_PAP iff AffinStruct(# the U1 of X, the CONGR of X #) is Pappian ) by A1; :: thesis: verum