let X be OrtAfPl; ( AffinStruct(# the carrier of X, the CONGR of X #) is translational implies X is satisfying_des )
assume A1:
AffinStruct(# the carrier of X, the CONGR of X #) is translational
; X is satisfying_des
let a be Element of X; CONMETR:def 8 for a1, b, b1, c, c1 being Element of X st not LIN a,a1,b & not LIN a,a1,c & a,a1 // b,b1 & a,a1 // c,c1 & a,b // a1,b1 & a,c // a1,c1 holds
b,c // b1,c1
let a1, b, b1, c, c1 be Element of X; ( not LIN a,a1,b & not LIN a,a1,c & a,a1 // b,b1 & a,a1 // c,c1 & a,b // a1,b1 & a,c // a1,c1 implies b,c // b1,c1 )
assume that
A2:
not LIN a,a1,b
and
A3:
not LIN a,a1,c
and
A4:
a,a1 // b,b1
and
A5:
a,a1 // c,c1
and
A6:
a,b // a1,b1
and
A7:
a,c // a1,c1
; b,c // b1,c1
reconsider a9 = a, a19 = a1, b9 = b, b19 = b1, c9 = c, c19 = c1 as Element of AffinStruct(# the carrier of X, the CONGR of X #) ;
LIN a9,a19,a19
by AFF_1:7;
then consider A9 being Subset of AffinStruct(# the carrier of X, the CONGR of X #) such that
A8:
A9 is being_line
and
A9:
a9 in A9
and
A10:
a19 in A9
and
a19 in A9
by AFF_1:21;
A11:
a9,b9 // a19,b19
by A6, ANALMETR:36;
b,b1 // a,a1
by A4, ANALMETR:59;
then A12:
b9,b19 // a9,a19
by ANALMETR:36;
A13:
a9 <> a19
then
for x9 being Element of AffinStruct(# the carrier of X, the CONGR of X #) holds
( x9 in A9 iff LIN a9,a19,x9 )
by A8, A9, A10, AFF_1:21, AFF_1:25;
then
A9 = Line (a9,a19)
by AFF_1:def 2;
then A14:
b9,b19 // A9
by A13, A12, AFF_1:def 4;
A15:
a9,c9 // a19,c19
by A7, ANALMETR:36;
c,c1 // a,a1
by A5, ANALMETR:59;
then A16:
c9,c19 // a9,a19
by ANALMETR:36;
A17:
a9 <> a19
then
for x9 being Element of AffinStruct(# the carrier of X, the CONGR of X #) holds
( x9 in A9 iff LIN a9,a19,x9 )
by A8, A9, A10, AFF_1:21, AFF_1:25;
then
A9 = Line (a9,a19)
by AFF_1:def 2;
then A18:
c9,c19 // A9
by A17, A16, AFF_1:def 4;
LIN c9,c19,c19
by AFF_1:7;
then consider N9 being Subset of AffinStruct(# the carrier of X, the CONGR of X #) such that
A19:
N9 is being_line
and
A20:
c9 in N9
and
A21:
c19 in N9
and
c19 in N9
by AFF_1:21;
LIN b9,b19,b19
by AFF_1:7;
then consider M9 being Subset of AffinStruct(# the carrier of X, the CONGR of X #) such that
A22:
M9 is being_line
and
A23:
b9 in M9
and
A24:
b19 in M9
and
b19 in M9
by AFF_1:21;
A25:
( A9 <> M9 & A9 <> N9 )
proof
assume
(
A9 = M9 or
A9 = N9 )
;
contradiction
then
(
LIN a9,
a19,
b9 or
LIN a9,
a19,
c9 )
by A8, A9, A10, A23, A20, AFF_1:21;
hence
contradiction
by A2, A3, ANALMETR:40;
verum
end;
A26:
c9 <> c19
proof
assume
c9 = c19
;
contradiction
then
c,
a // c,
a1
by A7, ANALMETR:59;
then
LIN c,
a,
a1
by ANALMETR:def 10;
then
LIN c9,
a9,
a19
by ANALMETR:40;
then
LIN a9,
a19,
c9
by AFF_1:6;
hence
contradiction
by A3, ANALMETR:40;
verum
end;
then
for x9 being Element of AffinStruct(# the carrier of X, the CONGR of X #) holds
( x9 in N9 iff LIN c9,c19,x9 )
by A19, A20, A21, AFF_1:21, AFF_1:25;
then
N9 = Line (c9,c19)
by AFF_1:def 2;
then A27:
A9 // N9
by A18, A26, AFF_1:def 5;
A28:
b9 <> b19
proof
assume
b9 = b19
;
contradiction
then
b,
a // b,
a1
by A6, ANALMETR:59;
then
LIN b,
a,
a1
by ANALMETR:def 10;
then
LIN b9,
a9,
a19
by ANALMETR:40;
then
LIN a9,
a19,
b9
by AFF_1:6;
hence
contradiction
by A2, ANALMETR:40;
verum
end;
then
for x9 being Element of AffinStruct(# the carrier of X, the CONGR of X #) holds
( x9 in M9 iff LIN b9,b19,x9 )
by A22, A23, A24, AFF_1:21, AFF_1:25;
then
M9 = Line (b9,b19)
by AFF_1:def 2;
then
A9 // M9
by A14, A28, AFF_1:def 5;
then
b9,c9 // b19,c19
by A1, A8, A9, A10, A22, A23, A24, A19, A20, A21, A27, A25, A11, A15;
hence
b,c // b1,c1
by ANALMETR:36; verum