thus F is_naturally_transformable_to F ; :: according to NATTRA_1:def 8 :: thesis: for a, b being Object of A st Hom (a,b) <> {} holds
for f being Morphism of a,b holds ((id F) . b) * (F /. f) = (F /. f) * ((id F) . a)
thus for a, b being Object of A st Hom (a,b) <> {} holds
for f being Morphism of a,b holds ((id F) . b) * (F /. f) = (F /. f) * ((id F) . a) by Lm1; :: thesis: verum