let n be Element of NAT ; for C being non empty Subset of (TOP-REAL n)
for E being Subset of I(01) st ex p1, p2 being Point of I[01] st
( p1 < p2 & E = [.p1,p2.] ) & I(01) | E,(TOP-REAL n) | C are_homeomorphic holds
ex s1, s2 being Point of (TOP-REAL n) st C is_an_arc_of s1,s2
let C be non empty Subset of (TOP-REAL n); for E being Subset of I(01) st ex p1, p2 being Point of I[01] st
( p1 < p2 & E = [.p1,p2.] ) & I(01) | E,(TOP-REAL n) | C are_homeomorphic holds
ex s1, s2 being Point of (TOP-REAL n) st C is_an_arc_of s1,s2
let E be Subset of I(01); ( ex p1, p2 being Point of I[01] st
( p1 < p2 & E = [.p1,p2.] ) & I(01) | E,(TOP-REAL n) | C are_homeomorphic implies ex s1, s2 being Point of (TOP-REAL n) st C is_an_arc_of s1,s2 )
given p1, p2 being Point of I[01] such that A1:
p1 < p2
and
A2:
E = [.p1,p2.]
; ( not I(01) | E,(TOP-REAL n) | C are_homeomorphic or ex s1, s2 being Point of (TOP-REAL n) st C is_an_arc_of s1,s2 )
A3:
I[01] ,I(01) | E are_homeomorphic
by A1, A2, Th67;
assume A4:
I(01) | E,(TOP-REAL n) | C are_homeomorphic
; ex s1, s2 being Point of (TOP-REAL n) st C is_an_arc_of s1,s2
not E is empty
by A1, A2, Th49;
then
I[01] ,(TOP-REAL n) | C are_homeomorphic
by A4, A3, BORSUK_3:3;
then consider g being Function of I[01],((TOP-REAL n) | C) such that
A5:
g is being_homeomorphism
by T_0TOPSP:def 1;
set s1 = g . 0;
set s2 = g . 1;
0 in the carrier of I[01]
by BORSUK_1:43;
then A6:
g . 0 in the carrier of ((TOP-REAL n) | C)
by FUNCT_2:5;
1 in the carrier of I[01]
by BORSUK_1:43;
then A7:
g . 1 in the carrier of ((TOP-REAL n) | C)
by FUNCT_2:5;
the carrier of ((TOP-REAL n) | C) c= the carrier of (TOP-REAL n)
by BORSUK_1:1;
then reconsider s1 = g . 0, s2 = g . 1 as Point of (TOP-REAL n) by A6, A7;
C is_an_arc_of s1,s2
by A5, TOPREAL1:def 1;
hence
ex s1, s2 being Point of (TOP-REAL n) st C is_an_arc_of s1,s2
; verum