let h1, h2 be Function of the carrier' of C,(Maps (Hom C)); ( ( for f being Morphism of C holds h1 . f = [[(Hom a,(dom f)),(Hom a,(cod f))],(hom a,f)] ) & ( for f being Morphism of C holds h2 . f = [[(Hom a,(dom f)),(Hom a,(cod f))],(hom a,f)] ) implies h1 = h2 )
assume that
A4:
for f being Morphism of C holds h1 . f = [[(Hom a,(dom f)),(Hom a,(cod f))],(hom a,f)]
and
A5:
for f being Morphism of C holds h2 . f = [[(Hom a,(dom f)),(Hom a,(cod f))],(hom a,f)]
; h1 = h2
hence
h1 = h2
by FUNCT_2:113; verum