let UA be Universal_Algebra; :: thesis: for h being Function st dom h = UAAut UA & ( for x being set st x in UAAut UA holds
h . x = 0 .--> x ) holds
rng h = MSAAut (MSAlg UA)
let h be Function; :: thesis: ( dom h = UAAut UA & ( for x being set st x in UAAut UA holds
h . x = 0 .--> x ) implies rng h = MSAAut (MSAlg UA) )
assume A1:
( dom h = UAAut UA & ( for x being set st x in UAAut UA holds
h . x = 0 .--> x ) )
; :: thesis: rng h = MSAAut (MSAlg UA)
thus
rng h c= MSAAut (MSAlg UA)
:: according to XBOOLE_0:def 10 :: thesis: MSAAut (MSAlg UA) c= rng hproof
let x be
set ;
:: according to TARSKI:def 3 :: thesis: ( not x in rng h or x in MSAAut (MSAlg UA) )
assume
x in rng h
;
:: thesis: x in MSAAut (MSAlg UA)
then consider q being
set such that A2:
(
q in dom h &
x = h . q )
by FUNCT_1:def 5;
A3:
x = 0 .--> q
by A1, A2;
0 .--> q is
ManySortedFunction of
(MSAlg UA),
(MSAlg UA)
by A1, A2, Th39;
then consider d being
ManySortedFunction of
(MSAlg UA),
(MSAlg UA) such that A4:
d = x
by A3;
consider q' being
Element of
UAAut UA such that A5:
q' = q
by A1, A2;
q' is_isomorphism UA,
UA
by Def1;
then A6:
MSAlg q' is_isomorphism MSAlg UA,
(MSAlg UA) Over (MSSign UA)
by MSUHOM_1:20;
MSAlg q' =
0 .--> q
by A5, MSUHOM_1:def 3
.=
x
by A1, A2
;
then
d is_isomorphism MSAlg UA,
MSAlg UA
by A4, A6, MSUHOM_1:9;
hence
x in MSAAut (MSAlg UA)
by A4, Def7;
:: thesis: verum
end;
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in MSAAut (MSAlg UA) or x in rng h )
assume A7:
x in MSAAut (MSAlg UA)
; :: thesis: x in rng h
then reconsider f = x as ManySortedFunction of (MSAlg UA),(MSAlg UA) by Def6;
A8:
f is_isomorphism MSAlg UA, MSAlg UA
by A7, Def7;
reconsider g = (*--> 0 ) * (signature UA) as Function of (dom (signature UA)),({0 } * ) by MSUALG_1:7;
( the carrier of (MSSign UA) = {0 } & the carrier' of (MSSign UA) = dom (signature UA) & the Arity of (MSSign UA) = g & the ResultSort of (MSSign UA) = (dom (signature UA)) --> 0 )
by MSUALG_1:def 13;
then A9:
f = 0 .--> (f . 0 )
by Th12;
ex q being set st
( q in dom h & x = h . q )
hence
x in rng h
by FUNCT_1:def 5; :: thesis: verum