let S be Subset of (TOP-REAL 2); ( S is Jordan implies ( S ` <> {} & ex A1, A2 being Subset of (TOP-REAL 2) ex C1, C2 being Subset of ((TOP-REAL 2) | (S `)) st
( S ` = A1 \/ A2 & A1 misses A2 & (Cl A1) \ A1 = (Cl A2) \ A2 & C1 = A1 & C2 = A2 & C1 is a_component & C2 is a_component & ( for C3 being Subset of ((TOP-REAL 2) | (S `)) holds
( not C3 is a_component or C3 = C1 or C3 = C2 ) ) ) ) )
assume A1:
S is Jordan
; ( S ` <> {} & ex A1, A2 being Subset of (TOP-REAL 2) ex C1, C2 being Subset of ((TOP-REAL 2) | (S `)) st
( S ` = A1 \/ A2 & A1 misses A2 & (Cl A1) \ A1 = (Cl A2) \ A2 & C1 = A1 & C2 = A2 & C1 is a_component & C2 is a_component & ( for C3 being Subset of ((TOP-REAL 2) | (S `)) holds
( not C3 is a_component or C3 = C1 or C3 = C2 ) ) ) )
then reconsider S9 = S ` as non empty Subset of (TOP-REAL 2) ;
consider A1, A2 being Subset of (TOP-REAL 2) such that
A2:
S ` = A1 \/ A2
and
A3:
A1 misses A2
and
A4:
(Cl A1) \ A1 = (Cl A2) \ A2
and
A5:
for C1, C2 being Subset of ((TOP-REAL 2) | (S `)) st C1 = A1 & C2 = A2 holds
( C1 is a_component & C2 is a_component )
by A1;
A6:
A1 c= S `
by A2, XBOOLE_1:7;
A7:
A2 c= S `
by A2, XBOOLE_1:7;
A8:
[#] ((TOP-REAL 2) | (S `)) = S `
by PRE_TOPC:def 5;
A1 c= [#] ((TOP-REAL 2) | (S `))
by A6, PRE_TOPC:def 5;
then reconsider G0A = A1, G0B = A2 as Subset of ((TOP-REAL 2) | S9) by A7, PRE_TOPC:def 5;
A9:
G0A = A1
;
G0B = A2
;
then A10:
G0A is a_component
by A5;
A11:
G0B is a_component
by A5, A9;
hence
( S ` <> {} & ex A1, A2 being Subset of (TOP-REAL 2) ex C1, C2 being Subset of ((TOP-REAL 2) | (S `)) st
( S ` = A1 \/ A2 & A1 misses A2 & (Cl A1) \ A1 = (Cl A2) \ A2 & C1 = A1 & C2 = A2 & C1 is a_component & C2 is a_component & ( for C3 being Subset of ((TOP-REAL 2) | (S `)) holds
( not C3 is a_component or C3 = C1 or C3 = C2 ) ) ) )
by A2, A3, A4, A10, A11; verum