let AP be AffinPlane; ( AP is satisfying_pap iff AP is satisfying_pap_1 )
hereby ( AP is satisfying_pap_1 implies AP is satisfying_pap )
assume A2:
AP is
satisfying_pap
;
AP is satisfying_pap_1 thus
AP is
satisfying_pap_1
verumproof
let M be
Subset of
AP;
AFF_2:def 14 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 & a,b9 // b,a9 & b,c9 // c,b9 & a,c9 // c,a9 & a9 <> b9 holds
c9 in Nlet 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 & a,b9 // b,a9 & b,c9 // c,b9 & a,c9 // c,a9 & a9 <> b9 holds
c9 in Nlet 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 & a,b9 // b,a9 & b,c9 // c,b9 & a,c9 // c,a9 & a9 <> b9 implies c9 in N )
assume that A3:
M is
being_line
and A4:
N is
being_line
and A5:
a in M
and A6:
b in M
and A7:
c in M
and A8:
M // N
and A9:
M <> N
and A10:
a9 in N
and A11:
b9 in N
and A12:
a,
b9 // b,
a9
and A13:
b,
c9 // c,
b9
and A14:
a,
c9 // c,
a9
and A15:
a9 <> b9
;
c9 in N
A16:
c <> a9
by A7, A8, A9, A10, AFF_1:59;
set C =
Line (
c,
b9);
A17:
c <> b9
by A7, A8, A9, A11, AFF_1:59;
then
Line (
c,
b9) is
being_line
by AFF_1:38;
then consider K being
Subset of
AP such that A18:
b in K
and A19:
Line (
c,
b9)
// K
by AFF_1:63;
A20:
(
c in Line (
c,
b9) &
b9 in Line (
c,
b9) )
by A17, AFF_1:38;
A21:
not
K // N
K is
being_line
by A19, AFF_1:50;
then consider x being
Element of
AP such that A22:
x in K
and A23:
x in N
by A4, A21, AFF_1:72;
A24:
b,
x // c,
b9
by A20, A18, A19, A22, AFF_1:53;
then
a,
x // c,
a9
by A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A23, Def13;
then
a,
x // a,
c9
by A14, A16, AFF_1:14;
then
LIN a,
x,
c9
by AFF_1:def 1;
then A25:
LIN c9,
x,
a
by AFF_1:15;
A26:
a <> b
proof
assume
a = b
;
contradiction
then
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 A4, A10, A11, AFF_1:39;
hence
contradiction
by A5, A8, A9, A15, AFF_1:59;
verum
end;
A27:
c9 <> b
b,
x // b,
c9
by A13, A17, A24, AFF_1:14;
then
LIN b,
x,
c9
by AFF_1:def 1;
then A28:
LIN c9,
x,
b
by AFF_1:15;
assume A29:
not
c9 in N
;
contradiction
LIN c9,
x,
c9
by AFF_1:16;
then
c9 in M
by A3, A5, A6, A29, A26, A23, A25, A28, AFF_1:17, AFF_1:39;
then
b9 in M
by A3, A6, A7, A13, A27, AFF_1:62;
hence
contradiction
by A8, A9, A11, AFF_1:59;
verum
end;
end;
assume A30:
AP is satisfying_pap_1
; AP is satisfying_pap
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,a9
let 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,a9
let 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
A31:
M is being_line
and
A32:
N is being_line
and
A33:
a in M
and
A34:
b in M
and
A35:
c in M
and
A36:
( M // N & M <> N )
and
A37:
a9 in N
and
A38:
b9 in N
and
A39:
c9 in N
and
A40:
a,b9 // b,a9
and
A41:
b,c9 // c,b9
; a,c9 // c,a9
set A = Line (c,a9);
set D = Line (b,c9);
A42:
b <> c9
by A34, A36, A39, AFF_1:59;
then A43:
( b in Line (b,c9) & c9 in Line (b,c9) )
by AFF_1:38;
assume A44:
not a,c9 // c,a9
; contradiction
then A45:
c <> a9
by AFF_1:12;
then A46:
c in Line (c,a9)
by AFF_1:38;
A47:
a9 in Line (c,a9)
by A45, AFF_1:38;
A48:
Line (c,a9) is being_line
by A45, AFF_1:38;
then consider P being Subset of AP such that
A49:
a in P
and
A50:
Line (c,a9) // P
by AFF_1:63;
A51:
a9 <> b9
proof
assume A52:
a9 = b9
;
contradiction
then
a9,
a // a9,
b
by A40, AFF_1:13;
then
LIN a9,
a,
b
by AFF_1:def 1;
then
LIN a,
b,
a9
by AFF_1:15;
then
(
a = b or
a9 in M )
by A31, A33, A34, AFF_1:39;
hence
contradiction
by A36, A37, A41, A44, A52, AFF_1:59;
verum
end;
A53:
not Line (b,c9) // P
proof
assume
Line (
b,
c9)
// P
;
contradiction
then
c,
b9 // P
by A41, A42, A43, AFF_1:46, AFF_1:54;
then
c,
b9 // Line (
c,
a9)
by A50, AFF_1:57;
then
b9 in Line (
c,
a9)
by A48, A46, AFF_1:37;
then
c in N
by A32, A37, A38, A51, A48, A46, A47, AFF_1:30;
hence
contradiction
by A35, A36, AFF_1:59;
verum
end;
A54:
Line (b,c9) is being_line
by A42, AFF_1:38;
P is being_line
by A50, AFF_1:50;
then consider x being Element of AP such that
A55:
x in Line (b,c9)
and
A56:
x in P
by A54, A53, AFF_1:72;
LIN b,x,c9
by A54, A43, A55, AFF_1:33;
then
b,x // b,c9
by AFF_1:def 1;
then A57:
b,x // c,b9
by A41, A42, AFF_1:14;
a,x // c,a9
by A46, A47, A49, A50, A56, AFF_1:53;
then
x in N
by A30, A31, A32, A33, A34, A35, A36, A37, A38, A40, A51, A57, Def14;
then
( x = c9 or b in N )
by A32, A39, A54, A43, A55, AFF_1:30;
hence
contradiction
by A34, A36, A44, A46, A47, A49, A50, A56, AFF_1:53, AFF_1:59; verum