let P, P1, P2, P19, P29 be Subset of the carrier of (TOP-REAL 2); for p1, p2 being Point of (TOP-REAL 2) st P is being_simple_closed_curve & P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = P & P19 is_an_arc_of p1,p2 & P29 is_an_arc_of p1,p2 & P19 \/ P29 = P & not ( P1 = P19 & P2 = P29 ) holds
( P1 = P29 & P2 = P19 )
let p1, p2 be Point of (TOP-REAL 2); ( P is being_simple_closed_curve & P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 \/ P2 = P & P19 is_an_arc_of p1,p2 & P29 is_an_arc_of p1,p2 & P19 \/ P29 = P & not ( P1 = P19 & P2 = P29 ) implies ( P1 = P29 & P2 = P19 ) )
assume that
A1:
P is being_simple_closed_curve
and
A2:
P1 is_an_arc_of p1,p2
and
A3:
P2 is_an_arc_of p1,p2
and
A4:
P1 \/ P2 = P
and
A5:
P19 is_an_arc_of p1,p2
and
A6:
P29 is_an_arc_of p1,p2
and
A7:
P19 \/ P29 = P
; ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )
reconsider P = P as Simple_closed_curve by A1;
A8:
p1 <> p2
by A6, Th37;
A9:
p1 in P19
by A5, TOPREAL1:1;
A10:
p2 in P19
by A5, TOPREAL1:1;
A11:
p1 in P2
by A3, TOPREAL1:1;
A12:
p2 in P2
by A3, TOPREAL1:1;
A13:
p1 in P1
by A2, TOPREAL1:1;
A14:
p2 in P1
by A2, TOPREAL1:1;
A15:
P1 c= P
by A4, XBOOLE_1:7;
A16:
[#] ((TOP-REAL 2) | P) = P
by PRE_TOPC:def 5;
P1 \ {p1,p2} c= P1
by XBOOLE_1:36;
then reconsider Q1 = P1 \ {p1,p2} as Subset of ((TOP-REAL 2) | P) by A15, A16, XBOOLE_1:1;
A17:
P2 c= P
by A4, XBOOLE_1:7;
P2 \ {p1,p2} c= P2
by XBOOLE_1:36;
then reconsider Q2 = P2 \ {p1,p2} as Subset of ((TOP-REAL 2) | P) by A16, A17, XBOOLE_1:1;
A18:
P19 c= P
by A7, XBOOLE_1:7;
P19 \ {p1,p2} c= P19
by XBOOLE_1:36;
then reconsider Q19 = P19 \ {p1,p2} as Subset of ((TOP-REAL 2) | P) by A16, A18, XBOOLE_1:1;
A19:
P29 c= P
by A7, XBOOLE_1:7;
P29 \ {p1,p2} c= P29
by XBOOLE_1:36;
then reconsider Q29 = P29 \ {p1,p2} as Subset of ((TOP-REAL 2) | P) by A16, A19, XBOOLE_1:1;
A20:
Q1 \/ Q2 = P \ {p1,p2}
by A4, XBOOLE_1:42;
A21:
Q19 \/ Q29 = P \ {p1,p2}
by A7, XBOOLE_1:42;
then A22:
Q19 \/ (Q1 \/ Q2) = Q1 \/ Q2
by A20, XBOOLE_1:7, XBOOLE_1:12;
A23:
Q29 \/ (Q1 \/ Q2) = Q1 \/ Q2
by A20, A21, XBOOLE_1:7, XBOOLE_1:12;
A24:
Q1 \/ (Q19 \/ Q29) = Q19 \/ Q29
by A20, A21, XBOOLE_1:7, XBOOLE_1:12;
A25:
Q2 \/ (Q19 \/ Q29) = Q19 \/ Q29
by A20, A21, XBOOLE_1:7, XBOOLE_1:12;
[#] ((TOP-REAL 2) | P1) = P1
by PRE_TOPC:def 5;
then reconsider R1 = Q1 as Subset of ((TOP-REAL 2) | P1) by XBOOLE_1:36;
R1 is connected
by A2, Th40;
then A26:
Q1 is connected
by A4, Th41, XBOOLE_1:7;
[#] ((TOP-REAL 2) | P2) = P2
by PRE_TOPC:def 5;
then reconsider R2 = Q2 as Subset of ((TOP-REAL 2) | P2) by XBOOLE_1:36;
R2 is connected
by A3, Th40;
then A27:
Q2 is connected
by A4, Th41, XBOOLE_1:7;
[#] ((TOP-REAL 2) | P19) = P19
by PRE_TOPC:def 5;
then reconsider R19 = Q19 as Subset of ((TOP-REAL 2) | P19) by XBOOLE_1:36;
R19 is connected
by A5, Th40;
then A28:
Q19 is connected
by A7, Th41, XBOOLE_1:7;
[#] ((TOP-REAL 2) | P29) = P29
by PRE_TOPC:def 5;
then reconsider R29 = Q29 as Subset of ((TOP-REAL 2) | P29) by XBOOLE_1:36;
R29 is connected
by A6, Th40;
then A29:
Q29 is connected
by A7, Th41, XBOOLE_1:7;
A30:
{p1,p2} c= P1
by A13, A14, TARSKI:def 2;
A31:
{p1,p2} c= P2
by A11, A12, TARSKI:def 2;
A32:
{p1,p2} c= P19
by A9, A10, TARSKI:def 2;
A33:
{p1,p2} c= P29
A34:
Q1 \/ {p1,p2} = P1
by A30, XBOOLE_1:45;
A35:
Q2 \/ {p1,p2} = P2
by A31, XBOOLE_1:45;
A36:
Q19 \/ {p1,p2} = P19
by A32, XBOOLE_1:45;
A37:
Q29 \/ {p1,p2} = P29
by A33, XBOOLE_1:45;
now ( ( not P1 = P29 or not P2 = P19 ) & not ( P1 = P19 & P2 = P29 ) implies ( P1 = P29 & P2 = P19 ) )assume A38:
( not
P1 = P29 or not
P2 = P19 )
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )now ( ( P1 <> P29 & ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) ) ) or ( P2 <> P19 & ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) ) ) )per cases
( P1 <> P29 or P2 <> P19 )
by A38;
case A39:
P1 <> P29
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )A40:
now ( Q1 \ Q29 = {} implies not Q29 \ Q1 = {} )end; now ( ( Q1 \ Q29 <> {} & ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) ) ) or ( Q29 \ Q1 <> {} & ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) ) ) )per cases
( Q1 \ Q29 <> {} or Q29 \ Q1 <> {} )
by A40;
case A44:
Q1 \ Q29 <> {}
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )set y = the
Element of
Q1 \ Q29;
A45:
the
Element of
Q1 \ Q29 in Q1
by A44, XBOOLE_0:def 5;
then A46:
the
Element of
Q1 \ Q29 in Q19 \/ Q29
by A20, A21, XBOOLE_0:def 3;
not the
Element of
Q1 \ Q29 in Q29
by A44, XBOOLE_0:def 5;
then
the
Element of
Q1 \ Q29 in Q19
by A46, XBOOLE_0:def 3;
then
Q1 /\ Q19 <> {}
by A45, XBOOLE_0:def 4;
then A47:
Q1 meets Q19
;
now not Q2 meets Q19assume
Q2 meets Q19
;
contradictionthen
(Q1 \/ Q19) \/ Q2 is
connected
by A26, A27, A28, A47, JORDAN1:4;
hence
contradiction
by A8, A13, A14, A15, A20, A22, Th47, XBOOLE_1:4;
verum end; then A48:
Q2 /\ Q19 = {}
;
A49:
Q2 c= Q29
Q19 c= Q1
hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
by A2, A3, A5, A6, A34, A35, A36, A37, A49, Th46, XBOOLE_1:9;
verum end; case A52:
Q29 \ Q1 <> {}
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )set y = the
Element of
Q29 \ Q1;
A53:
the
Element of
Q29 \ Q1 in Q29
by A52, XBOOLE_0:def 5;
then A54:
the
Element of
Q29 \ Q1 in Q2 \/ Q1
by A20, A21, XBOOLE_0:def 3;
not the
Element of
Q29 \ Q1 in Q1
by A52, XBOOLE_0:def 5;
then
the
Element of
Q29 \ Q1 in Q2
by A54, XBOOLE_0:def 3;
then
Q29 /\ Q2 <> {}
by A53, XBOOLE_0:def 4;
then A55:
Q29 meets Q2
;
now not Q19 meets Q2assume
Q19 meets Q2
;
contradictionthen
(Q29 \/ Q2) \/ Q19 is
connected
by A27, A28, A29, A55, JORDAN1:4;
hence
contradiction
by A8, A13, A14, A15, A21, A25, Th47, XBOOLE_1:4;
verum end; then A56:
Q19 /\ Q2 = {}
;
A57:
Q19 c= Q1
Q2 c= Q29
hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
by A2, A3, A5, A6, A34, A35, A36, A37, A57, Th46, XBOOLE_1:9;
verum end; end; end; hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
;
verum end; case A60:
P2 <> P19
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )A61:
now ( Q2 \ Q19 = {} implies not Q19 \ Q2 = {} )end; now ( ( Q2 \ Q19 <> {} & ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) ) ) or ( Q19 \ Q2 <> {} & ( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) ) ) )per cases
( Q2 \ Q19 <> {} or Q19 \ Q2 <> {} )
by A61;
case A65:
Q2 \ Q19 <> {}
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )set y = the
Element of
Q2 \ Q19;
A66:
the
Element of
Q2 \ Q19 in Q2
by A65, XBOOLE_0:def 5;
then A67:
the
Element of
Q2 \ Q19 in Q29 \/ Q19
by A20, A21, XBOOLE_0:def 3;
not the
Element of
Q2 \ Q19 in Q19
by A65, XBOOLE_0:def 5;
then
the
Element of
Q2 \ Q19 in Q29
by A67, XBOOLE_0:def 3;
then
Q2 /\ Q29 <> {}
by A66, XBOOLE_0:def 4;
then A68:
Q2 meets Q29
;
now not Q1 meets Q29assume
Q1 meets Q29
;
contradictionthen
(Q2 \/ Q29) \/ Q1 is
connected
by A26, A27, A29, A68, JORDAN1:4;
hence
contradiction
by A8, A13, A14, A15, A20, A23, Th47, XBOOLE_1:4;
verum end; then A69:
Q1 /\ Q29 = {}
;
A70:
Q1 c= Q19
Q29 c= Q2
hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
by A2, A3, A5, A6, A34, A35, A36, A37, A70, Th46, XBOOLE_1:9;
verum end; case A73:
Q19 \ Q2 <> {}
;
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )set y = the
Element of
Q19 \ Q2;
A74:
the
Element of
Q19 \ Q2 in Q19
by A73, XBOOLE_0:def 5;
then A75:
the
Element of
Q19 \ Q2 in Q1 \/ Q2
by A20, A21, XBOOLE_0:def 3;
not the
Element of
Q19 \ Q2 in Q2
by A73, XBOOLE_0:def 5;
then
the
Element of
Q19 \ Q2 in Q1
by A75, XBOOLE_0:def 3;
then
Q19 /\ Q1 <> {}
by A74, XBOOLE_0:def 4;
then A76:
Q19 meets Q1
;
now not Q29 meets Q1assume
Q29 meets Q1
;
contradictionthen
(Q19 \/ Q1) \/ Q29 is
connected
by A26, A28, A29, A76, JORDAN1:4;
hence
contradiction
by A8, A13, A14, A15, A21, A24, Th47, XBOOLE_1:4;
verum end; then A77:
Q29 /\ Q1 = {}
;
A78:
Q29 c= Q2
Q1 c= Q19
hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
by A2, A3, A5, A6, A34, A35, A36, A37, A78, Th46, XBOOLE_1:9;
verum end; end; end; hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
;
verum end; end; end; hence
( (
P1 = P19 &
P2 = P29 ) or (
P1 = P29 &
P2 = P19 ) )
;
verum end;
hence
( ( P1 = P19 & P2 = P29 ) or ( P1 = P29 & P2 = P19 ) )
; verum