let P be Subset of (TOP-REAL 2); :: thesis: for p1, p2, q1, q2 being Point of (TOP-REAL 2) st P is_an_arc_of p1,p2 & q1 in P & q2 in P & q1 <> p1 & q1 <> p2 & q2 <> p1 & q2 <> p2 holds
ex f being Path of q1,q2 st
( rng f c= P & rng f misses {p1,p2} )
let p1, p2, q1, q2 be Point of (TOP-REAL 2); :: thesis: ( P is_an_arc_of p1,p2 & q1 in P & q2 in P & q1 <> p1 & q1 <> p2 & q2 <> p1 & q2 <> p2 implies ex f being Path of q1,q2 st
( rng f c= P & rng f misses {p1,p2} ) )
assume that
A1:
P is_an_arc_of p1,p2
and
A2:
( q1 in P & q2 in P )
and
A3:
( q1 <> p1 & q1 <> p2 & q2 <> p1 & q2 <> p2 )
; :: thesis: ex f being Path of q1,q2 st
( rng f c= P & rng f misses {p1,p2} )
per cases
( q1 = q2 or q1 <> q2 )
;
suppose
q1 <> q2
;
:: thesis: ex f being Path of q1,q2 st
( rng f c= P & rng f misses {p1,p2} )then consider Q being non
empty Subset of
(TOP-REAL 2) such that A5:
Q is_an_arc_of q1,
q2
and A6:
(
Q c= P &
Q misses {p1,p2} )
by A1, A2, A3, JORDAN16:38;
consider g being
Path of
q1,
q2,
f being
Function of
I[01] ,
((TOP-REAL 2) | Q) such that A7:
(
rng f = Q &
g = f )
by A5, Th42;
reconsider h =
f as
Function of
I[01] ,
(TOP-REAL 2) by TOPREALA:28;
the
carrier of
((TOP-REAL 2) | Q) = Q
by PRE_TOPC:29;
then reconsider z1 =
q1,
z2 =
q2 as
Point of
((TOP-REAL 2) | Q) by A5, TOPREAL1:4;
A8:
z1,
z2 are_connected
f is
Path of
z1,
z2
then reconsider h =
h as
Path of
q1,
q2 by A8, TOPALG_2:1;
take
h
;
:: thesis: ( rng h c= P & rng h misses {p1,p2} )thus
(
rng h c= P &
rng h misses {p1,p2} )
by A6, A7;
:: thesis: verum end; end;