let G be addGroup; for a, b, c being Element of G st a,b are_conjugated & b,c are_conjugated holds
a,c are_conjugated
let a, b, c be Element of G; ( a,b are_conjugated & b,c are_conjugated implies a,c are_conjugated )
given g being Element of G such that A1:
a = b * g
; GROUP_1A:def 35 ( not b,c are_conjugated or a,c are_conjugated )
given h being Element of G such that A2:
b = c * h
; GROUP_1A:def 35 a,c are_conjugated
a = c * (h + g)
by A1, A2, Th24;
hence
a,c are_conjugated
; verum