let R be Ring; for a being Element of R holds Class ((EqRel (R,([#] R))),a) = the carrier of R
let a be Element of R; Class ((EqRel (R,([#] R))),a) = the carrier of R
set E = EqRel (R,([#] R));
thus
Class ((EqRel (R,([#] R))),a) c= the carrier of R
; XBOOLE_0:def 10 the carrier of R c= Class ((EqRel (R,([#] R))),a)
let x be object ; TARSKI:def 3 ( not x in the carrier of R or x in Class ((EqRel (R,([#] R))),a) )
assume
x in the carrier of R
; x in Class ((EqRel (R,([#] R))),a)
then reconsider x = x as Element of R ;
x - a in [#] R
;
then
[x,a] in EqRel (R,([#] R))
by Def5;
hence
x in Class ((EqRel (R,([#] R))),a)
by EQREL_1:19; verum