let C be Category; for D being Categorial Category
for F being Functor of C,D
for T being TargetCat of F -indexing_of C holds F = (F -indexing_of C) -functor (C,T)
let D be Categorial Category; for F being Functor of C,D
for T being TargetCat of F -indexing_of C holds F = (F -indexing_of C) -functor (C,T)
let F be Functor of C,D; for T being TargetCat of F -indexing_of C holds F = (F -indexing_of C) -functor (C,T)
set I = F -indexing_of C;
let T be TargetCat of F -indexing_of C; F = (F -indexing_of C) -functor (C,T)
A1:
dom F = the carrier' of C
by FUNCT_2:def 1;
A2:
now for x being object st x in the carrier' of C holds
F . x = ((F -indexing_of C) -functor (C,T)) . xlet x be
object ;
( x in the carrier' of C implies F . x = ((F -indexing_of C) -functor (C,T)) . x )assume
x in the
carrier' of
C
;
F . x = ((F -indexing_of C) -functor (C,T)) . xthen reconsider f =
x as
Morphism of
C ;
set h =
F . f;
A3:
(
dom (F . f) = (Obj F) . (dom f) &
cod (F . f) = (Obj F) . (cod f) )
by CAT_1:69;
A4:
(
dom (F . f) = (F . f) `11 &
cod (F . f) = (F . f) `12 )
by CAT_5:13;
then consider g being
Functor of
(F . f) `11 ,
(F . f) `12 such that A5:
F . f = [[((F . f) `11),((F . f) `12)],g]
by CAT_5:def 6;
((F -indexing_of C) `2) . f =
(F . f) `2
by A1, MCART_1:def 13
.=
g
by A5
;
hence
F . x = ((F -indexing_of C) -functor (C,T)) . x
by A4, A5, A3, Def11;
verum end;
thus
F = (F -indexing_of C) -functor (C,T)
by A2; verum