let T be non empty TopSpace; ( T is having_trivial_Fundamental_Group implies for t being Point of T
for P, Q being Loop of t holds P,Q are_homotopic )
assume A1:
T is having_trivial_Fundamental_Group
; for t being Point of T
for P, Q being Loop of t holds P,Q are_homotopic
let t be Point of T; for P, Q being Loop of t holds P,Q are_homotopic
let P, Q be Loop of t; P,Q are_homotopic
set E = EqRel (T,t);
A2:
pi_1 (T,t) is trivial
by A1, Def1;
( Class ((EqRel (T,t)),P) in the carrier of (pi_1 (T,t)) & Class ((EqRel (T,t)),Q) in the carrier of (pi_1 (T,t)) )
by TOPALG_1:47;
then
Class ((EqRel (T,t)),P) = Class ((EqRel (T,t)),Q)
by A2, ZFMISC_1:def 10;
hence
P,Q are_homotopic
by TOPALG_1:46; verum