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 A1:
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 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:
a,
b9 // b,
a9
and A12:
b,
c9 // c,
b9
and A13:
a,
c9 // c,
a9
and A14:
a9 <> b9
;
c9 in N
A15:
c <> a9
by A6, A7, A8, A9, AFF_1:45;
set C =
Line (
c,
b9);
A16:
c <> b9
by A6, A7, A8, A10, AFF_1:45;
then
Line (
c,
b9) is
being_line
by AFF_1:24;
then consider K being
Subset of
AP such that A17:
b in K
and A18:
Line (
c,
b9)
// K
by AFF_1:49;
A19:
(
c in Line (
c,
b9) &
b9 in Line (
c,
b9) )
by A16, AFF_1:24;
A20:
not
K // N
K is
being_line
by A18, AFF_1:36;
then consider x being
Element of
AP such that A21:
x in K
and A22:
x in N
by A3, A20, AFF_1:58;
A23:
b,
x // c,
b9
by A19, A17, A18, A21, AFF_1:39;
then
a,
x // c,
a9
by A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A22;
then
a,
x // a,
c9
by A13, A15, AFF_1:5;
then
LIN a,
x,
c9
by AFF_1:def 1;
then A24:
LIN c9,
x,
a
by AFF_1:6;
A25:
a <> b
proof
assume
a = b
;
contradiction
then
LIN a,
b9,
a9
by A11, AFF_1:def 1;
then
LIN a9,
b9,
a
by AFF_1:6;
then
(
a9 = b9 or
a in N )
by A3, A9, A10, AFF_1:25;
hence
contradiction
by A4, A7, A8, A14, AFF_1:45;
verum
end;
A26:
c9 <> b
b,
x // b,
c9
by A12, A16, A23, AFF_1:5;
then
LIN b,
x,
c9
by AFF_1:def 1;
then A27:
LIN c9,
x,
b
by AFF_1:6;
assume A28:
not
c9 in N
;
contradiction
LIN c9,
x,
c9
by AFF_1:7;
then
c9 in M
by A2, A4, A5, A28, A25, A22, A24, A27, AFF_1:8, AFF_1:25;
then
b9 in M
by A2, A5, A6, A12, A26, AFF_1:48;
hence
contradiction
by A7, A8, A10, AFF_1:45;
verum
end;
end;
assume A29:
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
A30:
M is being_line
and
A31:
N is being_line
and
A32:
a in M
and
A33:
b in M
and
A34:
c in M
and
A35:
( M // N & M <> N )
and
A36:
a9 in N
and
A37:
b9 in N
and
A38:
c9 in N
and
A39:
a,b9 // b,a9
and
A40:
b,c9 // c,b9
; a,c9 // c,a9
set A = Line (c,a9);
set D = Line (b,c9);
A41:
b <> c9
by A33, A35, A38, AFF_1:45;
then A42:
( b in Line (b,c9) & c9 in Line (b,c9) )
by AFF_1:24;
assume A43:
not a,c9 // c,a9
; contradiction
then A44:
c <> a9
by AFF_1:3;
then A45:
c in Line (c,a9)
by AFF_1:24;
A46:
a9 in Line (c,a9)
by A44, AFF_1:24;
A47:
Line (c,a9) is being_line
by A44, AFF_1:24;
then consider P being Subset of AP such that
A48:
a in P
and
A49:
Line (c,a9) // P
by AFF_1:49;
A50:
a9 <> b9
proof
assume A51:
a9 = b9
;
contradiction
then
a9,
a // a9,
b
by A39, AFF_1:4;
then
LIN a9,
a,
b
by AFF_1:def 1;
then
LIN a,
b,
a9
by AFF_1:6;
then
(
a = b or
a9 in M )
by A30, A32, A33, AFF_1:25;
hence
contradiction
by A35, A36, A40, A43, A51, AFF_1:45;
verum
end;
A52:
not Line (b,c9) // P
proof
assume
Line (
b,
c9)
// P
;
contradiction
then
c,
b9 // P
by A40, A41, A42, AFF_1:32, AFF_1:40;
then
c,
b9 // Line (
c,
a9)
by A49, AFF_1:43;
then
b9 in Line (
c,
a9)
by A47, A45, AFF_1:23;
then
c in N
by A31, A36, A37, A50, A47, A45, A46, AFF_1:18;
hence
contradiction
by A34, A35, AFF_1:45;
verum
end;
A53:
Line (b,c9) is being_line
by A41, AFF_1:24;
P is being_line
by A49, AFF_1:36;
then consider x being Element of AP such that
A54:
x in Line (b,c9)
and
A55:
x in P
by A53, A52, AFF_1:58;
LIN b,x,c9
by A53, A42, A54, AFF_1:21;
then
b,x // b,c9
by AFF_1:def 1;
then A56:
b,x // c,b9
by A40, A41, AFF_1:5;
a,x // c,a9
by A45, A46, A48, A49, A55, AFF_1:39;
then
x in N
by A29, A30, A31, A32, A33, A34, A35, A36, A37, A39, A50, A56;
then
( x = c9 or b in N )
by A31, A38, A53, A42, A54, AFF_1:18;
hence
contradiction
by A33, A35, A43, A45, A46, A48, A49, A55, AFF_1:39, AFF_1:45; verum