let AP be AffinPlane; ( AP is Pappian implies AP is satisfying_pap )
assume A1:
AP is Pappian
; AP is satisfying_pap
thus
AP is satisfying_pap
verumproof
let M be
Subset of
AP;
AFF_2:def 13 for N being Subset of AP
for a, b, c, a9, b9, c9 being Element of AP st M is being_line & N is being_line & a in M & b in M & c in M & M // N & M <> N & a9 in N & b9 in N & c9 in N & a,b9 // b,a9 & b,c9 // c,b9 holds
a,c9 // c,a9let N be
Subset of
AP;
for a, b, c, a9, b9, c9 being Element of AP st M is being_line & N is being_line & a in M & b in M & c in M & M // N & M <> N & a9 in N & b9 in N & c9 in N & a,b9 // b,a9 & b,c9 // c,b9 holds
a,c9 // c,a9let a,
b,
c,
a9,
b9,
c9 be
Element of
AP;
( M is being_line & N is being_line & a in M & b in M & c in M & M // N & M <> N & a9 in N & b9 in N & c9 in N & a,b9 // b,a9 & b,c9 // c,b9 implies a,c9 // c,a9 )
assume that A2:
M is
being_line
and A3:
N is
being_line
and A4:
a in M
and A5:
b in M
and A6:
c in M
and A7:
M // N
and A8:
M <> N
and A9:
a9 in N
and A10:
b9 in N
and A11:
c9 in N
and A12:
a,
b9 // b,
a9
and A13:
b,
c9 // c,
b9
;
a,c9 // c,a9
A14:
b <> a9
by A5, A7, A8, A9, AFF_1:59;
set K =
Line a,
c9;
set C =
Line c,
b9;
A15:
c <> b9
by A6, A7, A8, A10, AFF_1:59;
then A16:
Line c,
b9 is
being_line
by AFF_1:38;
assume A17:
not
a,
c9 // c,
a9
;
contradiction
A18:
now assume A19:
a = b
;
contradictionthen
LIN a,
b9,
a9
by A12, AFF_1:def 1;
then
LIN a9,
b9,
a
by AFF_1:15;
then
(
a9 = b9 or
a in N )
by A3, A9, A10, AFF_1:39;
hence
contradiction
by A4, A7, A8, A13, A17, A19, AFF_1:59;
verum end;
A20:
now assume
a9 = b9
;
contradictionthen
a9,
a // a9,
b
by A12, AFF_1:13;
then
LIN a9,
a,
b
by AFF_1:def 1;
then
LIN a,
b,
a9
by AFF_1:15;
then
a9 in M
by A2, A4, A5, A18, AFF_1:39;
hence
contradiction
by A7, A8, A9, AFF_1:59;
verum end;
A21:
now assume A22:
b = c
;
contradictionthen
LIN b,
c9,
b9
by A13, AFF_1:def 1;
then
LIN b9,
c9,
b
by AFF_1:15;
then
(
b9 = c9 or
b in N )
by A3, A10, A11, AFF_1:39;
hence
contradiction
by A5, A7, A8, A12, A17, A22, AFF_1:59;
verum end;
A23:
now assume
b9 = c9
;
contradictionthen
b9,
b // b9,
c
by A13, AFF_1:13;
then
LIN b9,
b,
c
by AFF_1:def 1;
then
LIN b,
c,
b9
by AFF_1:15;
then
b9 in M
by A2, A5, A6, A21, AFF_1:39;
hence
contradiction
by A7, A8, A10, AFF_1:59;
verum end;
A24:
a <> c9
by A4, A7, A8, A11, AFF_1:59;
then A25:
a in Line a,
c9
by AFF_1:38;
Line a,
c9 is
being_line
by A24, AFF_1:38;
then consider T being
Subset of
AP such that A26:
a9 in T
and A27:
Line a,
c9 // T
by AFF_1:63;
A28:
T is
being_line
by A27, AFF_1:50;
A29:
c9 in Line a,
c9
by A24, AFF_1:38;
A30:
(
c in Line c,
b9 &
b9 in Line c,
b9 )
by A15, AFF_1:38;
not
Line c,
b9 // T
proof
assume
Line c,
b9 // T
;
contradiction
then
Line c,
b9 // Line a,
c9
by A27, AFF_1:58;
then
c,
b9 // a,
c9
by A25, A29, A30, AFF_1:53;
then
b,
c9 // a,
c9
by A13, A15, AFF_1:14;
then
c9,
b // c9,
a
by AFF_1:13;
then
LIN c9,
b,
a
by AFF_1:def 1;
then
LIN a,
b,
c9
by AFF_1:15;
then
c9 in M
by A2, A4, A5, A18, AFF_1:39;
hence
contradiction
by A7, A8, A11, AFF_1:59;
verum
end;
then consider x being
Element of
AP such that A31:
x in Line c,
b9
and A32:
x in T
by A16, A28, AFF_1:72;
set D =
Line x,
b;
A33:
x <> b
proof
assume
x = b
;
contradiction
then
LIN b,
c,
b9
by A16, A30, A31, AFF_1:33;
then
b9 in M
by A2, A5, A6, A21, AFF_1:39;
hence
contradiction
by A7, A8, A10, AFF_1:59;
verum
end;
then A34:
b in Line x,
b
by AFF_1:38;
then A35:
Line x,
b <> N
by A5, A7, A8, AFF_1:59;
A36:
Line x,
b is
being_line
by A33, AFF_1:38;
A37:
x in Line x,
b
by A33, AFF_1:38;
not
Line x,
b // N
proof
assume
Line x,
b // N
;
contradiction
then
Line x,
b // M
by A7, AFF_1:58;
then
x in M
by A5, A37, A34, AFF_1:59;
then
(
c in T or
b9 in M )
by A2, A6, A16, A30, A31, A32, AFF_1:30;
hence
contradiction
by A7, A8, A10, A17, A25, A29, A26, A27, AFF_1:53, AFF_1:59;
verum
end;
then consider o being
Element of
AP such that A38:
o in Line x,
b
and A39:
o in N
by A3, A36, AFF_1:72;
LIN b9,
c,
x
by A16, A30, A31, AFF_1:33;
then A40:
b9,
c // b9,
x
by AFF_1:def 1;
A41:
a9 <> x
proof
assume
a9 = x
;
contradiction
then
b9,
a9 // b9,
c
by A40, AFF_1:13;
then
LIN b9,
a9,
c
by AFF_1:def 1;
then
c in N
by A3, A9, A10, A20, AFF_1:39;
hence
contradiction
by A6, A7, A8, AFF_1:59;
verum
end;
A42:
now assume
o = x
;
contradictionthen
N = T
by A3, A9, A26, A28, A32, A39, A41, AFF_1:30;
then
N = Line a,
c9
by A11, A29, A27, AFF_1:59;
hence
contradiction
by A4, A7, A8, A25, AFF_1:59;
verum end;
A43:
a,
c9 // x,
a9
by A25, A29, A26, A27, A32, AFF_1:53;
A44:
now assume
o = a9
;
contradictionthen
LIN a9,
b,
x
by A36, A37, A34, A38, AFF_1:33;
then
a9,
b // a9,
x
by AFF_1:def 1;
then
b,
a9 // x,
a9
by AFF_1:13;
then
a,
b9 // x,
a9
by A12, A14, AFF_1:14;
then
a,
b9 // a,
c9
by A43, A41, AFF_1:14;
then
LIN a,
b9,
c9
by AFF_1:def 1;
then
LIN b9,
c9,
a
by AFF_1:15;
then
a in N
by A3, A10, A11, A23, AFF_1:39;
hence
contradiction
by A4, A7, A8, AFF_1:59;
verum end;
c,
b9 // x,
b9
by A40, AFF_1:13;
then A45:
b,
c9 // x,
b9
by A13, A15, AFF_1:14;
A46:
a <> b9
by A4, A7, A8, A10, AFF_1:59;
not
a,
b9 // Line x,
b
proof
assume
a,
b9 // Line x,
b
;
contradiction
then
b,
a9 // Line x,
b
by A12, A46, AFF_1:46;
then
a9 in Line x,
b
by A36, A34, AFF_1:37;
then
b in T
by A26, A28, A32, A36, A37, A34, A41, AFF_1:30;
then
b,
a9 // a,
c9
by A25, A29, A26, A27, AFF_1:53;
then
a,
b9 // a,
c9
by A12, A14, AFF_1:14;
then
LIN a,
b9,
c9
by AFF_1:def 1;
then
LIN b9,
c9,
a
by AFF_1:15;
then
a in N
by A3, A10, A11, A23, AFF_1:39;
hence
contradiction
by A4, A7, A8, AFF_1:59;
verum
end;
then consider y being
Element of
AP such that A47:
y in Line x,
b
and A48:
LIN a,
b9,
y
by A36, AFF_1:73;
A49:
LIN a,
y,
a
by AFF_1:16;
A50:
b9 <> x
proof
assume
b9 = x
;
contradiction
then
a,
c9 // a9,
b9
by A25, A29, A26, A27, A32, AFF_1:53;
then
a,
c9 // N
by A3, A9, A10, A20, AFF_1:41;
then
c9,
a // N
by AFF_1:48;
then
a in N
by A3, A11, AFF_1:37;
hence
contradiction
by A4, A7, A8, AFF_1:59;
verum
end;
A51:
now assume
o = b9
;
contradictionthen
LIN b9,
x,
b
by A36, A37, A34, A38, AFF_1:33;
then
b9,
x // b9,
b
by AFF_1:def 1;
then
x,
b9 // b,
b9
by AFF_1:13;
then
b,
c9 // b,
b9
by A45, A50, AFF_1:14;
then
LIN b,
c9,
b9
by AFF_1:def 1;
then
LIN b9,
c9,
b
by AFF_1:15;
then
b in N
by A3, A10, A11, A23, AFF_1:39;
hence
contradiction
by A5, A7, A8, AFF_1:59;
verum end;
A52:
now assume
o = y
;
contradictionthen
LIN b9,
o,
a
by A48, AFF_1:15;
then
a in N
by A3, A10, A39, A51, AFF_1:39;
hence
contradiction
by A4, A7, A8, AFF_1:59;
verum end;
A53:
b <> c9
by A5, A7, A8, A11, AFF_1:59;
A54:
now assume
o = c9
;
contradictionthen
Line x,
b // Line c,
b9
by A13, A15, A53, A16, A30, A36, A34, A38, AFF_1:52;
then
b in Line c,
b9
by A31, A37, A34, AFF_1:59;
then
LIN c,
b,
b9
by A16, A30, AFF_1:33;
then
b9 in M
by A2, A5, A6, A21, AFF_1:39;
hence
contradiction
by A7, A8, A10, AFF_1:59;
verum end;
LIN b9,
a,
y
by A48, AFF_1:15;
then
b9,
a // b9,
y
by AFF_1:def 1;
then
a,
b9 // y,
b9
by AFF_1:13;
then A55:
y,
b9 // b,
a9
by A12, A46, AFF_1:14;
o <> b
by A5, A7, A8, A39, AFF_1:59;
then
y,
c9 // x,
a9
by A1, A3, A9, A10, A11, A36, A37, A34, A38, A39, A45, A47, A55, A35, A51, A44, A54, A42, A52, Def2;
then
y,
c9 // a,
c9
by A43, A41, AFF_1:14;
then
c9,
y // c9,
a
by AFF_1:13;
then
LIN c9,
y,
a
by AFF_1:def 1;
then A56:
LIN a,
y,
c9
by AFF_1:15;
LIN a,
y,
b9
by A48, AFF_1:15;
then
(
a in Line x,
b or
a in N )
by A3, A10, A11, A23, A47, A56, A49, AFF_1:17, AFF_1:39;
then
Line x,
b // N
by A2, A4, A5, A7, A8, A18, A36, A34, AFF_1:30, AFF_1:59;
hence
contradiction
by A38, A39, A35, AFF_1:59;
verum
end;