let n be Nat; for P being Subset of (TOP-REAL n)
for p1, p2 being Point of (TOP-REAL n) st P is_an_arc_of p1,p2 holds
P is connected
let P be Subset of (TOP-REAL n); for p1, p2 being Point of (TOP-REAL n) st P is_an_arc_of p1,p2 holds
P is connected
let p1, p2 be Point of (TOP-REAL n); ( P is_an_arc_of p1,p2 implies P is connected )
assume A1:
P is_an_arc_of p1,p2
; P is connected
then consider f being Function of I[01],((TOP-REAL n) | P) such that
A2:
f is being_homeomorphism
and
f . 0 = p1
and
f . 1 = p2
by TOPREAL1:def 1;
reconsider P9 = P as non empty Subset of (TOP-REAL n) by A1, TOPREAL1:1;
A3:
f is continuous Function of I[01],((TOP-REAL n) | P9)
by A2, TOPS_2:def 5;
A4:
[#] I[01] is connected
by CONNSP_1:27, TREAL_1:19;
A5:
rng f = [#] ((TOP-REAL n) | P)
by A2, TOPS_2:def 5;
A6:
[#] ((TOP-REAL n) | P) = P
by PRE_TOPC:def 5;
dom f = [#] I[01]
by A2, TOPS_2:def 5;
then A7:
P = f .: ([#] I[01])
by A5, A6, RELAT_1:113;
f .: ([#] I[01]) is connected
by A3, A4, TOPS_2:61;
hence
P is connected
by A7, CONNSP_1:23; verum