let n be Element of NAT ; for T being non empty convex SubSpace of TOP-REAL n
for a being Point of T
for C being Loop of a holds the carrier of (pi_1 (T,a)) = {(Class ((EqRel (T,a)),C))}
let T be non empty convex SubSpace of TOP-REAL n; for a being Point of T
for C being Loop of a holds the carrier of (pi_1 (T,a)) = {(Class ((EqRel (T,a)),C))}
let a be Point of T; for C being Loop of a holds the carrier of (pi_1 (T,a)) = {(Class ((EqRel (T,a)),C))}
let C be Loop of a; the carrier of (pi_1 (T,a)) = {(Class ((EqRel (T,a)),C))}
set E = EqRel (T,a);
hereby TARSKI:def 3,
XBOOLE_0:def 10 {(Class ((EqRel (T,a)),C))} c= the carrier of (pi_1 (T,a))
let x be
object ;
( x in the carrier of (pi_1 (T,a)) implies x in {(Class ((EqRel (T,a)),C))} )assume
x in the
carrier of
(pi_1 (T,a))
;
x in {(Class ((EqRel (T,a)),C))}then consider P being
Loop of
a such that A1:
x = Class (
(EqRel (T,a)),
P)
by TOPALG_1:47;
P,
C are_homotopic
by Th2;
then
x = Class (
(EqRel (T,a)),
C)
by A1, TOPALG_1:46;
hence
x in {(Class ((EqRel (T,a)),C))}
by TARSKI:def 1;
verum
end;
let x be object ; TARSKI:def 3 ( not x in {(Class ((EqRel (T,a)),C))} or x in the carrier of (pi_1 (T,a)) )
assume
x in {(Class ((EqRel (T,a)),C))}
; x in the carrier of (pi_1 (T,a))
then A2:
x = Class ((EqRel (T,a)),C)
by TARSKI:def 1;
C in Loops a
by TOPALG_1:def 1;
then
x in Class (EqRel (T,a))
by A2, EQREL_1:def 3;
hence
x in the carrier of (pi_1 (T,a))
by TOPALG_1:def 5; verum