let M be non empty multMagma ; ex X being non empty set ex r being Relators of (free_magma X) ex g being Function of ((free_magma X) ./. (equ_rel r)),M st
( g is bijective & g is multiplicative )
set X = the carrier of M;
consider f being Function of (free_magma the carrier of M),M such that
A1:
( f is multiplicative & f extends (id the carrier of M) * ((canon_image the carrier of M,1) " ) )
by Th40;
consider r being Relators of (free_magma the carrier of M) such that
A2:
equ_kernel f = equ_rel r
by A1, Th5;
reconsider R = equ_kernel f as compatible Equivalence_Relation of (free_magma the carrier of M) by A1, Th4;
dom the multF of M c= [:the carrier of M,the carrier of M:]
;
then
the multF of M = the multF of M | [:the carrier of M,the carrier of M:]
by RELAT_1:97;
then
the multF of M = the multF of M || the carrier of M
by REALSET1:def 3;
then reconsider H = M as non empty multSubmagma of M by Def10;
for y being set st y in the carrier of M holds
ex x being set st
( x in dom f & y = f . x )
proof
let y be
set ;
( y in the carrier of M implies ex x being set st
( x in dom f & y = f . x ) )
assume A3:
y in the
carrier of
M
;
ex x being set st
( x in dom f & y = f . x )
set x =
[y,1];
take
[y,1]
;
( [y,1] in dom f & y = f . [y,1] )
[:(free_magma the carrier of M,1),{1}:] c= the
carrier of
(free_magma the carrier of M)
by Lm1;
then A4:
[:the carrier of M,{1}:] c= the
carrier of
(free_magma the carrier of M)
by Def14;
1
in {1}
by TARSKI:def 1;
then
[y,1] in [:the carrier of M,{1}:]
by A3, ZFMISC_1:def 2;
then
[y,1] in the
carrier of
(free_magma the carrier of M)
by A4;
hence
[y,1] in dom f
by FUNCT_2:def 1;
y = f . [y,1]
A5:
(
dom ((id the carrier of M) * ((canon_image the carrier of M,1) " )) c= dom f &
f tolerates (id the carrier of M) * ((canon_image the carrier of M,1) " ) )
by A1, Def3;
A6:
(canon_image the carrier of M,1) . y = [y,1]
by A3, Lm2;
y in dom (canon_image the carrier of M,1)
by A3, Lm2;
then
[y,1] in rng (canon_image the carrier of M,1)
by A6, FUNCT_1:12;
then A7:
[y,1] in dom ((canon_image the carrier of M,1) " )
by FUNCT_1:55;
the
carrier of
M c= dom (id the carrier of M)
by FUNCT_2:def 1;
then
dom (canon_image the carrier of M,1) c= dom (id the carrier of M)
by Lm2;
then
rng ((canon_image the carrier of M,1) " ) c= dom (id the carrier of M)
by FUNCT_1:55;
then A8:
[y,1] in dom ((id the carrier of M) * ((canon_image the carrier of M,1) " ))
by A7, RELAT_1:46;
A9:
y in dom (canon_image the carrier of M,1)
by A3, Lm2;
thus y =
(id the carrier of M) . y
by A3, FUNCT_1:35
.=
(id the carrier of M) . (((canon_image the carrier of M,1) " ) . [y,1])
by A9, FUNCT_1:56, A6
.=
((id the carrier of M) * ((canon_image the carrier of M,1) " )) . [y,1]
by A8, FUNCT_1:22
.=
f . [y,1]
by A8, A5, PARTFUN1:132
;
verum
end;
then
the carrier of M c= rng f
by FUNCT_1:19;
then
the carrier of H = rng f
by XBOOLE_0:def 10;
then consider g being Function of ((free_magma the carrier of M) ./. R),H such that
A10:
( f = g * (nat_hom R) & g is bijective & g is multiplicative )
by A1, Th42;
reconsider g = g as Function of ((free_magma the carrier of M) ./. (equ_rel r)),M by A2;
take
the carrier of M
; ex r being Relators of (free_magma the carrier of M) ex g being Function of ((free_magma the carrier of M) ./. (equ_rel r)),M st
( g is bijective & g is multiplicative )
take
r
; ex g being Function of ((free_magma the carrier of M) ./. (equ_rel r)),M st
( g is bijective & g is multiplicative )
take
g
; ( g is bijective & g is multiplicative )
thus
( g is bijective & g is multiplicative )
by A10, A2; verum