consider I29 being non empty set , B9 being ManySortedSet of I29, f9 being Function of [: the carrier of C1, the carrier of C1:],I29 such that
A1:
the ObjectMap of F = f9
and
A2:
the Arrows of C2 = B9
and
A3:
the MorphMap of F is ManySortedFunction of the Arrows of C1,B9 * f9
by Def3;
A4: the Arrows of C1 . [o1,o2] =
the Arrows of C1 . (o1,o2)
.=
<^o1,o2^>
by ALTCAT_1:def 1
;
A5:
[o1,o2] in [: the carrier of C1, the carrier of C1:]
by ZFMISC_1:87;
the ObjectMap of F is Contravariant
by Def13;
then consider g being Function of the carrier of C1, the carrier of C2 such that
A6:
the ObjectMap of F = ~ [:g,g:]
;
A7:
dom f9 = [: the carrier of C1, the carrier of C1:]
by FUNCT_2:def 1;
then
[o1,o1] in dom (~ [:g,g:])
by A1, A6, ZFMISC_1:87;
then
[o1,o1] in dom [:g,g:]
by FUNCT_4:42;
then A8: F . o1 =
([:g,g:] . (o1,o1)) `1
by A6, FUNCT_4:def 2
.=
[(g . o1),(g . o1)] `1
by FUNCT_3:75
.=
g . o1
;
[o2,o2] in dom (~ [:g,g:])
by A1, A6, A7, ZFMISC_1:87;
then
[o2,o2] in dom [:g,g:]
by FUNCT_4:42;
then A9: F . o2 =
([:g,g:] . (o2,o2)) `1
by A6, FUNCT_4:def 2
.=
[(g . o2),(g . o2)] `1
by FUNCT_3:75
.=
g . o2
;
[o1,o2] in dom (~ [:g,g:])
by A1, A6, A7, ZFMISC_1:87;
then A10:
[o2,o1] in dom [:g,g:]
by FUNCT_4:42;
(B9 * f9) . [o1,o2] =
B9 . (f9 . (o1,o2))
by A5, A7, FUNCT_1:13
.=
B9 . ([:g,g:] . (o2,o1))
by A1, A6, A10, FUNCT_4:def 2
.=
the Arrows of C2 . ((F . o2),(F . o1))
by A2, A8, A9, FUNCT_3:75
.=
<^(F . o2),(F . o1)^>
by ALTCAT_1:def 1
;
hence
Morph-Map (F,o1,o2) is Function of <^o1,o2^>,<^(F . o2),(F . o1)^>
by A3, A4, A5, PBOOLE:def 15; verum