let A be non empty transitive AltCatStr ; for B, C being non empty with_units AltCatStr
for F being feasible Covariant FunctorStr of A,B
for G being FunctorStr of B,C
for o, o1 being object of A holds Morph-Map (G * F),o,o1 = (Morph-Map G,(F . o),(F . o1)) * (Morph-Map F,o,o1)
let B, C be non empty with_units AltCatStr ; for F being feasible Covariant FunctorStr of A,B
for G being FunctorStr of B,C
for o, o1 being object of A holds Morph-Map (G * F),o,o1 = (Morph-Map G,(F . o),(F . o1)) * (Morph-Map F,o,o1)
let F be feasible Covariant FunctorStr of A,B; for G being FunctorStr of B,C
for o, o1 being object of A holds Morph-Map (G * F),o,o1 = (Morph-Map G,(F . o),(F . o1)) * (Morph-Map F,o,o1)
let G be FunctorStr of B,C; for o, o1 being object of A holds Morph-Map (G * F),o,o1 = (Morph-Map G,(F . o),(F . o1)) * (Morph-Map F,o,o1)
let o, o1 be object of A; Morph-Map (G * F),o,o1 = (Morph-Map G,(F . o),(F . o1)) * (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 4;
then dom (the MorphMap of G * the ObjectMap of F) =
dom the ObjectMap of F
by RELAT_1:46
.=
[: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_1:106;
then A2: (the MorphMap of G * the ObjectMap of F) . [o,o1] =
the MorphMap of G . (the ObjectMap of F . o,o1)
by FUNCT_1:22
.=
Morph-Map G,(F . o),(F . o1)
by FUNCTOR0:23
;
dom the MorphMap of F = [:the carrier of A,the carrier of A:]
by PARTFUN1:def 4;
then
[o,o1] in dom the MorphMap of F
by ZFMISC_1:106;
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 24;
thus Morph-Map (G * F),o,o1 =
((the MorphMap of G * the ObjectMap of F) ** the MorphMap of F) . o,o1
by FUNCTOR0:def 37
.=
(Morph-Map G,(F . o),(F . o1)) * (Morph-Map F,o,o1)
by A3, A2, PBOOLE:def 24
; verum