let A be non empty transitive AltCatStr ; for B, C being non empty with_units AltCatStr
for F being feasible Contravariant FunctorStr over A,B
for G being FunctorStr over B,C
for o, o1 being Object of A holds Morph-Map ((G * F),o,o1) = (Morph-Map (G,(F . o1),(F . o))) * (Morph-Map (F,o,o1))
let B, C be non empty with_units AltCatStr ; for F being feasible Contravariant FunctorStr over A,B
for G being FunctorStr over B,C
for o, o1 being Object of A holds Morph-Map ((G * F),o,o1) = (Morph-Map (G,(F . o1),(F . o))) * (Morph-Map (F,o,o1))
let F be feasible Contravariant FunctorStr over A,B; for G being FunctorStr over B,C
for o, o1 being Object of A holds Morph-Map ((G * F),o,o1) = (Morph-Map (G,(F . o1),(F . o))) * (Morph-Map (F,o,o1))
let G be FunctorStr over B,C; for o, o1 being Object of A holds Morph-Map ((G * F),o,o1) = (Morph-Map (G,(F . o1),(F . o))) * (Morph-Map (F,o,o1))
let o, o1 be Object of A; Morph-Map ((G * F),o,o1) = (Morph-Map (G,(F . o1),(F . o))) * (Morph-Map (F,o,o1))
( dom the MorphMap of G = [: the carrier of B, the carrier of B:] & rng the ObjectMap of F c= [: the carrier of B, the carrier of B:] )
by PARTFUN1:def 2;
then dom ( the MorphMap of G * the ObjectMap of F) =
dom the ObjectMap of F
by RELAT_1:27
.=
[: the carrier of A, the carrier of A:]
by FUNCT_2:def 1
;
then A1:
[o,o1] in dom ( the MorphMap of G * the ObjectMap of F)
by ZFMISC_1:87;
then A2: ( the MorphMap of G * the ObjectMap of F) . [o,o1] =
the MorphMap of G . ( the ObjectMap of F . (o,o1))
by FUNCT_1:12
.=
Morph-Map (G,(F . o1),(F . o))
by FUNCTOR0:23
;
dom the MorphMap of F = [: the carrier of A, the carrier of A:]
by PARTFUN1:def 2;
then
[o,o1] in dom the MorphMap of F
by ZFMISC_1:87;
then
[o,o1] in (dom ( the MorphMap of G * the ObjectMap of F)) /\ (dom the MorphMap of F)
by A1, XBOOLE_0:def 4;
then A3:
[o,o1] in dom (( the MorphMap of G * the ObjectMap of F) ** the MorphMap of F)
by PBOOLE:def 19;
thus Morph-Map ((G * F),o,o1) =
(( the MorphMap of G * the ObjectMap of F) ** the MorphMap of F) . (o,o1)
by FUNCTOR0:def 36
.=
(Morph-Map (G,(F . o1),(F . o))) * (Morph-Map (F,o,o1))
by A3, A2, PBOOLE:def 19
; verum